Subjects -> BIOLOGY (Total: 3397 journals)
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BIOLOGY (1617 journals)            First | 1 2 3 4 5 6 7 8 | Last

Showing 801 - 1000 of 1720 Journals sorted alphabetically
IRBM     Full-text available via subscription  
IRBM News     Full-text available via subscription  
iScience     Open Access  
Islets     Full-text available via subscription   (Followers: 1)
Israel Journal of Ecology and Evolution     Full-text available via subscription   (Followers: 1)
Istituto Lombardo - Accademia di Scienze e Lettere - Incontri di Studio     Open Access  
Italian Journal of Mycology     Open Access  
ITBM-RBM     Full-text available via subscription   (Followers: 1)
ITBM-RBM News     Full-text available via subscription   (Followers: 1)
IUBMB Life     Hybrid Journal   (Followers: 6)
IUFS Journal of Biology     Open Access  
Izvestiya Atmospheric and Oceanic Physics     Hybrid Journal   (Followers: 1)
Izvestiya, Physics of the Solid Earth     Hybrid Journal   (Followers: 2)
Jahangirnagar University Journal of Biological Sciences     Open Access   (Followers: 1)
Japanese Journal of Applied Physics     Full-text available via subscription   (Followers: 6)
JCI Insight     Open Access   (Followers: 3)
JDREAM : Journal of interDisciplinary REsearch Applied to Medicine     Open Access  
JETP Letters     Hybrid Journal   (Followers: 3)
Jornal Interdisciplinar de Biociências     Open Access  
Journal Biastatistics : Biomedics, Industry & Business And Social Statistics     Open Access  
Journal of Bacteriology & Parasitology     Open Access   (Followers: 5)
Journal of Bioanalysis & Biomedicine     Open Access   (Followers: 1)
Journal of Bioequivalence & Bioavailability     Open Access  
Journal of Bioremediation & Biodegradation     Open Access   (Followers: 4)
Journal of Computer Science & Systems Biology     Open Access   (Followers: 5)
Journal of Proteomics & Bioinformatics     Open Access   (Followers: 10)
Journal of Advanced Laboratory Research in Biology     Open Access   (Followers: 1)
Journal of Advances in Biology     Open Access   (Followers: 5)
Journal of Advances in Biology & Biotechnology     Open Access  
Journal of Agricultural, Biological & Environmental Statistics     Hybrid Journal   (Followers: 11)
Journal of Amino Acids     Open Access   (Followers: 4)
Journal of Anatomy     Hybrid Journal   (Followers: 7)
Journal of AOAC International     Full-text available via subscription   (Followers: 8)
Journal of Applied Biobehavioral Research     Hybrid Journal  
Journal of Applied Bioinformatics & Computational Biology     Hybrid Journal   (Followers: 5)
Journal of Applied Biological Sciences     Open Access   (Followers: 2)
Journal of Applied Biosciences     Open Access   (Followers: 1)
Journal of Applied Ichthyology     Hybrid Journal   (Followers: 6)
Journal of Applied Life Sciences International     Open Access  
Journal of Applied Phycology     Hybrid Journal   (Followers: 10)
Journal of Applied Virology     Open Access   (Followers: 5)
Journal of Aquatic Sciences     Full-text available via subscription   (Followers: 3)
Journal of Arachnology     Full-text available via subscription  
Journal of Asia-Pacific Biodiversity     Open Access  
Journal of Astrobiology & Outreach     Open Access   (Followers: 3)
Journal of Avian Biology     Hybrid Journal   (Followers: 24)
Journal of Basic Microbiology     Hybrid Journal   (Followers: 3)
Journal of Bio-Science     Open Access   (Followers: 3)
Journal of Biobased Materials and Bioenergy     Full-text available via subscription  
Journal of Biodiversity Management & Forestry     Hybrid Journal   (Followers: 6)
Journal of Bioenergetics and Biomembranes     Hybrid Journal   (Followers: 1)
Journal of Biogeography     Hybrid Journal   (Followers: 45)
Journal of Bioinformatics and Computational Biology     Hybrid Journal   (Followers: 18)
Journal of Bioinformatics and Intelligent Control     Full-text available via subscription   (Followers: 2)
Journal of Bioinformatics and Sequence Analysis     Open Access   (Followers: 1)
Journal of Biological Control     Hybrid Journal   (Followers: 2)
Journal of Biological Dynamics     Open Access   (Followers: 1)
Journal of Biological Education     Hybrid Journal   (Followers: 2)
Journal of Biological Engineering     Open Access   (Followers: 3)
Journal of Biological Methods     Open Access  
Journal of Biological Physics     Hybrid Journal   (Followers: 1)
Journal of Biological Research - Thessaloniki     Open Access  
Journal of Biological Sciences     Open Access   (Followers: 5)
Journal of Biological Systems     Hybrid Journal   (Followers: 2)
Journal of Biology and Life Science     Open Access   (Followers: 2)
Journal of Biology, Agriculture and Healthcare     Open Access   (Followers: 11)
Journal of Biomechanics     Hybrid Journal   (Followers: 41)
Journal of Biomedical Education     Open Access   (Followers: 2)
Journal of Biomedical Informatics     Partially Free   (Followers: 16)
Journal of Biomedical Informatics : X     Open Access  
Journal of Biomedical Materials Research Part A     Hybrid Journal   (Followers: 3)
Journal of Biomedical Materials Research Part B : Applied Biomaterials     Hybrid Journal   (Followers: 2)
Journal of Biomedical Nanotechnology     Full-text available via subscription   (Followers: 3)
Journal of Biomedical Physics and Engineering     Open Access  
Journal of Biomedical Science and Engineering     Open Access   (Followers: 2)
Journal of Bionic Engineering     Hybrid Journal  
Journal of Bioresource Management     Open Access  
Journal of Biorheology     Hybrid Journal  
Journal of Biosafety and Biosecurity     Open Access  
Journal of Bioscience and Bioengineering     Full-text available via subscription   (Followers: 34)
Journal of Biosciences and Medicines     Open Access   (Followers: 3)
Journal of Biosocial Science     Hybrid Journal   (Followers: 5)
Journal of Bryology     Hybrid Journal   (Followers: 7)
Journal of Cell Biology     Full-text available via subscription   (Followers: 48)
Journal of Cell Communication and Signaling     Hybrid Journal  
Journal of Cell Death     Open Access   (Followers: 2)
Journal of Cell Science     Full-text available via subscription   (Followers: 18)
Journal of Cellular Biochemistry     Hybrid Journal   (Followers: 4)
Journal of Cellular Physiology     Hybrid Journal   (Followers: 7)
Journal of Cerebral Blood Flow & Metabolism     Hybrid Journal   (Followers: 2)
Journal of Chromatography B     Hybrid Journal   (Followers: 34)
Journal of Clinical Bioinformatics     Open Access   (Followers: 5)
Journal of Clinical Toxicology     Open Access   (Followers: 6)
Journal of Communications Technology and Electronics     Hybrid Journal   (Followers: 2)
Journal of Contemporary Physics (Armenian Academy of Sciences)     Hybrid Journal   (Followers: 10)
Journal of Crustacean Biology     Hybrid Journal   (Followers: 2)
Journal of Developmental Biology     Open Access   (Followers: 2)
Journal of Ecology and The Natural Environment     Open Access   (Followers: 4)
Journal of Education, Health and Sport     Open Access   (Followers: 4)
Journal of Electrical Bioimpedance     Open Access   (Followers: 2)
Journal of Electromyography and Kinesiology     Hybrid Journal   (Followers: 5)
Journal of Environment and Ecology     Open Access   (Followers: 10)
Journal of Environment and Sociobiology     Hybrid Journal  
Journal of Environmental Analysis and Progress     Open Access  
Journal of Environmental Radioactivity     Hybrid Journal   (Followers: 3)
Journal of Environmental Science and Natural Resources     Open Access   (Followers: 4)
Journal of Ethnobiology     Full-text available via subscription   (Followers: 4)
Journal of Ethnobiology and Ethnomedicine     Open Access  
Journal of Ethology     Hybrid Journal   (Followers: 3)
Journal of Evolutionary Biology     Hybrid Journal   (Followers: 26)
Journal of Evolutionary Biology Research     Open Access  
Journal of Experimental and Clinical Anatomy     Open Access   (Followers: 2)
Journal of Experimental Life Science     Open Access  
Journal of Experimental Marine Biology and Ecology     Hybrid Journal   (Followers: 40)
Journal of Fish Biology     Hybrid Journal   (Followers: 36)
Journal of Functional Biomaterials     Open Access   (Followers: 3)
Journal of Fungi     Open Access   (Followers: 3)
Journal of Genomics     Open Access   (Followers: 1)
Journal of Great Lakes Research     Hybrid Journal   (Followers: 7)
Journal of Green Science and Technology     Full-text available via subscription   (Followers: 2)
Journal of Health and Biological Sciences     Open Access   (Followers: 1)
Journal of Heredity     Hybrid Journal   (Followers: 3)
Journal of Huazhong University of Science and Technology [Medical Sciences]     Hybrid Journal  
Journal of Human Evolution     Hybrid Journal   (Followers: 18)
Journal of Hymenoptera Research     Open Access   (Followers: 3)
Journal of Ichthyology     Hybrid Journal   (Followers: 3)
Journal of Insect Behavior     Hybrid Journal   (Followers: 7)
Journal of Insect Biodiversity     Open Access   (Followers: 4)
Journal of Insect Conservation     Hybrid Journal   (Followers: 10)
Journal of Institute of Science and Technology     Open Access  
Journal of Integrated OMICS     Open Access  
Journal of Integrated Pest Management     Open Access   (Followers: 3)
Journal of Integrative Environmental Sciences     Hybrid Journal   (Followers: 4)
Journal of Intelligent Transportation Systems: Technology, Planning, and Operations     Hybrid Journal   (Followers: 4)
Journal of Invertebrate Pathology     Hybrid Journal   (Followers: 3)
Journal of Landscape Ecology     Open Access   (Followers: 18)
Journal of Law and the Biosciences     Open Access   (Followers: 4)
Journal of Leukocyte Biology     Open Access   (Followers: 2)
Journal of Life and Earth Science     Open Access  
Journal of Life Sciences Research     Open Access  
Journal of Lipid Research     Full-text available via subscription   (Followers: 6)
Journal of Lipids     Open Access  
Journal of Luminescence     Hybrid Journal   (Followers: 4)
Journal of Mammalian Evolution     Hybrid Journal   (Followers: 7)
Journal of Mammalian Ova Research     Full-text available via subscription  
Journal of Mammalogy     Full-text available via subscription   (Followers: 13)
Journal of Mammary Gland Biology and Neoplasia     Hybrid Journal   (Followers: 1)
Journal of Marine and Aquatic Sciences     Open Access   (Followers: 1)
Journal of Marine Sciences     Open Access   (Followers: 16)
Journal of Mathematical Biology     Hybrid Journal   (Followers: 9)
Journal of Mechanics in Medicine and Biology     Hybrid Journal  
Journal of Medical Primatology     Hybrid Journal   (Followers: 1)
Journal of Medical Toxicology     Hybrid Journal   (Followers: 6)
Journal of Medicinal Botany     Open Access  
Journal of Medicine and Philosophy     Hybrid Journal   (Followers: 8)
Journal of Melittology     Open Access   (Followers: 1)
Journal of Membrane Biology     Hybrid Journal   (Followers: 1)
Journal of Membrane Computing     Hybrid Journal  
Journal of Membrane Science     Hybrid Journal   (Followers: 25)
Journal of Molecular Biology     Hybrid Journal   (Followers: 45)
Journal of Molecular Biology Research     Open Access   (Followers: 3)
Journal of Molecular Catalysis B: Enzymatic     Hybrid Journal   (Followers: 1)
Journal of Molecular Cell Biology     Hybrid Journal   (Followers: 15)
Journal of Molecular Evolution     Hybrid Journal   (Followers: 6)
Journal of Molecular Signaling     Open Access  
Journal of Molecular Structure     Hybrid Journal   (Followers: 7)
Journal of Molluscan Studies     Hybrid Journal   (Followers: 1)
Journal of Muscle Research and Cell Motility     Hybrid Journal   (Followers: 1)
Journal of Nanoparticle Research     Hybrid Journal   (Followers: 3)
Journal of Nanoparticles     Open Access   (Followers: 3)
Journal of Natural History     Hybrid Journal   (Followers: 10)
Journal of Natural Products     Hybrid Journal   (Followers: 19)
Journal of Natural Science, Biology and Medicine     Open Access   (Followers: 3)
Journal of Natural Sciences and Mathematics Research     Open Access  
Journal of Natural Sciences Research     Open Access   (Followers: 4)
Journal of Negative Results in BioMedicine     Open Access  
Journal of Nematology     Open Access   (Followers: 1)
Journal of Neuroscience and Behavioral Health     Open Access   (Followers: 1)
Journal of New Results in Science     Open Access  
Journal of New Seeds     Hybrid Journal  
Journal of Nucleic Acids     Open Access   (Followers: 1)
Journal of Parasitology     Full-text available via subscription   (Followers: 13)
Journal of Parasitology and Vector Biology     Open Access   (Followers: 2)
Journal of Pharmacological and Toxicological Methods     Hybrid Journal   (Followers: 7)
Journal of Phycology     Hybrid Journal   (Followers: 6)
Journal of Physics D : Applied Physics     Hybrid Journal   (Followers: 13)
Journal of Physics: Condensed Matter     Hybrid Journal   (Followers: 6)
Journal of Physics: Conference Series     Open Access   (Followers: 2)
Journal of Phytopathology     Hybrid Journal   (Followers: 2)
Journal of Plankton Research     Hybrid Journal   (Followers: 2)
Journal of Plant Ecology     Hybrid Journal   (Followers: 20)
Journal of Plant Pathology     Hybrid Journal  
Journal of Plasma Physics     Hybrid Journal   (Followers: 22)
Journal of Pollination Ecology     Open Access  
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Progressive Research in Biology     Open Access   (Followers: 1)
Journal of Proteome Research     Hybrid Journal   (Followers: 12)
Journal of Proteomics     Hybrid Journal   (Followers: 10)
Journal of Purdue Undergraduate Research     Open Access   (Followers: 1)
Journal of Radiation Research and Applied Sciences     Open Access   (Followers: 2)

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Similar Journals
Journal Cover
Journal of Molecular Structure
Journal Prestige (SJR): 0.409
Citation Impact (citeScore): 2
Number of Followers: 7  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0022-2860 - ISSN (Online) 0022-2860
Published by Elsevier Homepage  [3161 journals]
  • Novel far UV–Vis absorbing bis(dihydrophenanthro[9,10-e][1,2,4]triazine)
           derivative dyes: Synthesis, optical, photophysical and solvatochromic
           properties
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Mahmoud E.M. Sakr, Maram T.H. Abou Kana, Ahmed H.M. Elwahy, Samy A. El-Daly, El-Zeiny M. EbeidIn this paper discussed novel fluorescent derivative dye in far UV–Vis range have been synthesized by bis-alkylation of starting compound 4, 12a-dihydrophenanthro [9, 10-e][1, 2,4]triazine-3(4H)-thione, with the appropriate dibromo compounds. and characterized by standard spectroscopic techniques. Their chemical structures were confirmed by 1HNMR, IR, MS and elemental analysis. Various optical characterizations were carried out in solvents of varying polarity. Optical parameters via extinction coefficient, absorption and emission cross-sections, fluorescence quantum yield, fluorescence lifetime, oscillator strength, the dipole moment, radiative decay rate constant, energy yield of fluorescence and the attenuation length has been determined. The effect of the spacer between two phenanthro[9,10-e][1,2,4]triazine units in new dye and solvent polarities upon the spectral properties are discussed. The ground-state (μg) and excited-state (μe) dipole moments were estimated using solvatochromic correlations. The higher value of Δμ may attribute to the singlet higher excited state of dyes which had strong intramolecular charge transfer character (ICT).Graphical abstractImage 104813
       
  • The effect of Ag nanoparticles on physical and photocatalytic properties
           of ZnFe2O4/SiO2 nanocomposite
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Mahmoud Naseri, Ahmad Kamalianfar, Ehsan Naderi, Azam HashemiThe present article aimed at synthesizing ZnFe2O4 nanoparticles by thermal treatment method. After ZnFe2O4 nanoparticles had been synthesized, SiO2 shell and SiO2–Ag nanoparticles were placed on them. At the next step, ZnFe2O4/SiO2 and ZnFe2O4/SiO2–Ag nanocomposites were characterized by structural and morphological features. Optical properties of ZnFe2O4/SiO2 and ZnFe2O4/SiO2–Ag nanocomposites were also investigated by derivation of absorption spectrum fitting and Tauc’s methods. Furthermore, the impact of SiO2 shell and Sio2-Ag nanoparticles on magnetic features of ZnFe2O4 nanoparticles was evaluated. The roles of reactive oxygen species (ROS) on degradation of MB dye solution in the presence and absence of H2O2 was also analyzed.Graphical abstractImage 1
       
  • Elucidation of site symmetry, location, bond, ground state of Cu2+ ions in
           lithium sulphate monohydrate single crystal through EPR and optical
           studies
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): P. Subramanian, K. Juliet sheela, S. Radha Krishnan, V.M. ShanmugamAbstractThe highly efficient non linear optical (NLO) lithium suphate monohydrate (LSMH) single crystal with well-developed faces is obtained in a few days by slow evaporation of aqueous solutions at room temperature. Small amount of copper II sulphate pentahydrate is added as the paramagnetic impurity into the system. The powder XRD study shows the monoclinic cell dimension of Cu2+ doped LSMH single crystal. Also FTIR analysis reveals the existence of host in a crystal. The single crystal EPR investigation talks about the presence of copper ion. Even though more than one site is noticed, two are followed and reported. The principle values g and A parameters were calculated for both the sites. The spin Hamiltonian parameters found for both the sites, indicate the rhombic local crystal field symmetry around the impurity ion Cu2+, which is further confirmed by optical absorption studies. Interestingly, both the paramagnetic ions enter the lattice interstitially. The type of bonding between the metal ligand bands for site I and site II are found to be moderate ionic and covalent nature. The ground state wave function of both the sites are observed as dx2−y2, which is also supported by Rache parameter and optical studies.
       
  • A structural, elastic, mechanical, spectroscopic, thermodynamic, and
           magnetic properties of polymer coated CoFe2O4 nanostructures for various
           applications
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Kamlesh V. Chandekar, Mohd. Shkir, S. AlFaifyThe polymer coated CoFe2O4 nanoparticles were prepared at 80 °C by co-precipitation route. X-ray diffraction (XRD) pattern of as-prepared samples confirmed formation of cobalt ferrite. The morphology of the samples was investigated by Transmission electron microscopy (TEM) showing nanoparticles of different shape and size with average particle size of 13.4 ± 2.2, 5.1 ± 1.8 and 11.2 ± 2.3 nm for CF-PEG, CF-PVA and CF-PVP respectively. Elastic moduli of as-prepared samples were estimated on the basis of tetrahedral and octahedral site appears in FTIR spectroscopy. Isotropic nature of polycrystals of as-prepared samples was investigated by estimating the universal anisotropic index AU=0, bulk anisotropic index AB=0, shear anisotropic indexAG=0, Zener anisotropic parameter Az=1 and Elastic anisotropic parameterγ=0. Thermodynamic property of as-prepared samples was investigated by evaluating the thermal conductivity which shows slightly decrease in CF-PVA sample. The magnetization of as-prepared samples in presence applied magnetic field of (±7T) was recorded and correlated with particle size of the sample. The spin canting angle was founded to be higher for CF-PVA compared to CF-PVP and CF-PEG sample.Graphical abstractImage 1057708
       
  • Millimeter wave free-jet spectrum of the isotopologues of 1,2-butanediol
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Assimo Maris, Laura B. Favero, Annalisa Vigorito, Camilla Calabrese, Luca Evangelisti, Sonia MelandriWe recorded the rotational spectra of six isotopologues of the most stable conformer of 1,2-butanediol in the 59.6–74.4 GHz frequency region. The observed species are the four monosubstituted 13C, the OD···OH and the OD···OD, and the measurements were performed using a Free-Jet Absorption Millimeter Wave spectrometer. The analysis of the 18 experimental rotational constants determined for all the isotopologues together with those of the parent species, lead to the determination of the coordinates in the principal axis system for the substituted atoms. From the theoretical structure, calculated at the B3LYP-D3/aug-cc-pVTZ level of theory, a refinement of the structural parameters led to a partial r0 geometry, which reproduced all the rotational constants within 1.3 MHz.Graphical abstractImage 104309
       
  • Structural change of trans-azobenzene crystal and powder under high
           pressure
    • Abstract: Publication date: Available online 16 January 2020Source: Journal of Molecular StructureAuthor(s): Aisen Li, Changjiang Bi, Shuping Xu, Haining Cui, Weiqing XuStructural changes in the trans-azobenzene single crystal and powder upon compression realized by a diamond anvil cell (DAC) were disclosed via the analysis of Raman spectroscopy. Compared to the shearing force that destroys the crystal structure of trans-azobenzene, the hydrostatic pressure makes the crystal structure of trans-azobenzene stacking more closely and orderly, which are proved by the blue-shifts of Raman bands. During the compression process, the peaks at 1159, 1182 and 1593 cm−1, highly related to C–H in-plane bending, C–C stretching and in-plane bending vibrations of benzene ring, show more obvious blue-shifts Δ = 21, 35 and 21 cm−1, respectively. Two types of trans-azobenzene under hydrostatic pressure display different spectral behaviors, due to the strong intermolecular interactions in their crystal forms, but not in powders. When the pressure was gradually reduced to the ambient pressure, the initial forms of the Raman spectra of trans-azobenzene were entirely recovered, indicating that the pressure-induced structural changes are reversible in a certain pressure range. Our spectroscopic observations enable a deeper understanding of the molecular interactions of azobenzene compounds.Graphical abstractImage 1
       
  • Substantial effect of Silk fibroin reinforcement on properties of
           Hydroxyapatite/Silk fibroin nanocomposite for bone tissue engineering
           application
    • Abstract: Publication date: Available online 15 January 2020Source: Journal of Molecular StructureAuthor(s): J. Mobika, M. Rajkumar, V. Nithya Priya, S.P. Linto SibiNano-biocomposites that mimics bone’s extracellular matrix with hydroxyapatite as an inorganic and silk fibroin as organic phase for three different ratios via a simple in-situ co-precipitation method have been synthesized. The silk fibroin, a biodegradable polymer from cocoons of Bombyx mori silkworm were extracted by employing a chemical-free High-Temperature High-Pressure method as a degumming route. Then followed by the regeneration process which was done by using calcium chloride-formic acid solvent system to replace time-consuming, cost-effective traditional methods. The prepared composites were structurally analyzed using Fourier Transform Infra-Red spectroscopy (FTIR) and X-ray Diffraction (XRD) techniques. The morphology and the elemental composition of the nano-biocomposites were examined using Field Emission Scanning Electron Microscopy (FESEM) and Energy-dispersive X-ray Spectroscopy (EDX). The in-vitro bioactivity of the bio-composites namely, swelling ratio, biodegradation and biomineralization ability is monitored in the presence of Simulated Body Fluid (SBF). Our observation demonstrate that silk fibroin concentration influences the formation of hydroxyapatite.Graphical abstractImage 1
       
  • A comprehensive molecular insight into host-guest interaction of
           Phenanthrene with native and ionic liquid modified β-cyclodextrins:
           Preparation and characterization in aqueous medium and solid state
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Boon Yih Hui, Nur Nadhirah Mohamad Zain, Sharifah Mohamad, Samikannu Prabu, Hasnah Osman, Muggundha RaoovAbstractThe inclusion complexes of Phenanthrene with native βCD and ionic liquid modified βCD were prepared and investigated in both solid and solution states. The formation of the inclusion complexes were successfully monitored by FTIR, TGA, DSC, 1D 1H NMR, 2D NOESY NMR and UV–vis spectroscopy. The results revealed that Phenanthrene formed 1:1 stoichiometry ratio for both host-guest inclusion complexes with an apparent formation constant of 239.7 M-1 for native β-cyclodextrin, which was higher than ionic liquid modified β-cyclodextrin (14.9 M-1). The NMR studies showed that Phenanthrene penetrated into the cavity of both cyclodextrins (CDs) from the more accessible wider side. For βCD, Phenanthrene displayed one mode of binding, i.e., formation of an inclusion complex. Meanwhile, ionic liquid modified β-cyclodextrin demonstrated two modes of binding, i.e. inclusion in the CD cavities and interaction with the outer surface of the CD molecules, mainly near the ionic liquid (IL) group.
       
  • Insights into supramolecular assembly formation of pyridine tetrazolium
           and aromatic acid assisted via hydrogen-bonding
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Yunlei Fu, Mingjuan Zhang, Huiqi Qu, Kang Liu, Zhaoxiang Zhang, Yu Yang, Bin Li, Fusheng Liu, Lei WangPyridyltetrazolium is an advantageous molecular precursor for its abundant coordination sites, which is adequate for the design of novel multi-dimensional structures. Three compounds of P-pyridyltetrazolium with 1,2,3-benzenetricarboxylic acid 1, M-pyridyltetrazolium with 1,2,3-benzenetricarboxylic acid 2, and P-pyridyltetrazolium with 2,3-dihydroxybenzoic acid 3 were synthesized and investigated. Compounds 1 and 2 indicated that the position of the coordination nitrogen atom will affect the structure of the supramolecule. Compound 1 finally formed a three-dimensional network through hydrogen bonds of O–H⋯O and O–H⋯N, whereas compound 2 formed a two-dimensional layered structure and water molecules play an important role in the construction of the two-dimensional layer. In addition to O–H⋯N hydrogen bond interaction, a weak C–H⋯C hydrogen bond also has significant effect on the construction of compound 3. Some main supramolecular synthons observed in three compounds were shown to construct most of these hydrogen bonding networks. The three compounds have been characterized by single crystal X-ray diffraction, 1H nuclear magnetic resonance, infrared spectroscopy and thermogravimetric analysis (TGA). Furthermore, their supramolecular structures are fully analyzed.Graphical abstractSupramolecular structures constructed by pyridinetetrazolium with aromatic acid.Image 1
       
  • Molecular structure, magnetic properties and catalytic activity in
           selective ethylene dimerization of nickel (II) complexes with
           bis(3,5-dimethylpyrazol-1-yl)methane
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Sergey V. Zubkevich, Vladislav A. Tuskaev, Svetlana Ch Gagieva, Alexander A. Pavlov, Viktor N. Khrustalev, Dmitriy N. Zarubin, Dmitriy A. Kurmaev, Nikolai A. Kolosov, Boris M. BulychevNickel(II) complexes with neutral bidentate nitrogen-containing ligands are of great interest as promising precatalysts for the selective oligomerization of ethylene. Complexes of compositions 0.75[LNiCl2]2•0.25[LNiClBr]2 2 and LNiBr2 3 where L = bis-(3,5-dimethylpyrazol-1-yl)methane have been synthesized and characterized by single crystal X-ray diffraction, IR and 1H NMR spectroscopies and elemental analysis. The 1H NMR spectra of paramagnetic complexes indicate that the structures of these complexes in solution are similar to ones in the solid state. Magnetic susceptibility of the compounds has been investigated and discussed in the context of their structures. Treatment of these complexes with diethylaluminum chloride (DEAC) or ethylaluminum sesquichloride (EASC) generates active catalysts that oligomerize ethylene to yield mostly butenes with activities up to 930 kg(oligomers)·mol[Ni]−1·h−1 (DEAC).Graphical abstractImage 1
       
  • New square-planar nickel(II)-triphenylphosphine complexes containing ONS
           donor ligands: Synthesis, characterization, electrochemical and
           antioxidant properties
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Yeliz Kaya, Ayşe Erçağ, Atıf KocaFive new mixed ligand nickel(II) complexes with the general formula [Ni(L)(PPh3)], [C1–C5], were prepared from the reaction of triphenylphosphine (PPh3) with ONS donor ligands (L) [where R = Η (L1); 4-OCH3 (L2); 4-OCH2(CH2)6CH3 (L3); 4-OCH3, 4′-CH3 (L4) and 4-OCH2CHCH2 (L5)] derived from 2-hydroxybenzophenones and thiocarbohydrazide. The structures of the complexes were characterized by elemental analysis, IR, 1H and 31P NMR spectroscopy, conductivity measurements. The crystal structures of ligand (L2) and complex (C2) were determined by single crystal X-ray diffraction method. The ligand is coordinated to the nickel core through the phenolate oxygen, azomethine nitrogen and sulfur atoms, while the fourth coordination site is occupied by the P atom of a triphenylphosphine ligand. X-ray analysis indicated distorted square-planar structure for the complex C2. Electrochemical behaviors of thiocarbohydrazone ligands (L1-L5) and their nickel(II) complexes (C1–C5) were studied and effects of the type of substituents were compared. All ligands illustrated two irreversible reductions and one irreversible oxidation. Complexing of the ligands with Ni(III) ion considerably influenced their redox behaviors. Electron transfer process of the complexes get easier and became more reversible when compared with those of the corresponding ligands. Moreover, Ni(II) complexes illustrated NiII/NiI and NiII/NiIII processes in addition to the ligand-based electron transfer reactions. In-situ spectroelectrochemical responses of the ligands considerably changed after formation of Ni(II) complexes. Total antioxidant capacity and free radical scavenging activity of the compounds have been tested using CUPRAC and DPPH methods, respectively. The results of Ni(II) complexes were compared with a standard antioxidant compound.Graphical abstractImage 1
       
  • Binuclear furanyl-azine metal complexes encapsulated in NaY zeolite as
           efficiently heterogeneous catalysts for phenol hydroxylation
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): I. Kuźniarska-Biernacka, M.M.M. Raposo, R.M.F. Batista, O.S.G.P. Soares, M.F.R. Pereira, P. Parpot, C. Oliveira, E. Skiba, E. Jartych, A.M. Fonseca, I.C. NevesTwo different methods A and B were used for preparing binuclear furanyl-azine metal complexes encapsulated in NaY zeolite. These new heterogeneous catalysts based on Fe(II) or Cu(II) complexes with a metal/ligand molar ratio of 2:1, were characterized by different spectroscopic techniques and chemical analysis which confirm the presence of the metal complexes inside the supercages of the zeolite. Mössbauer spectroscopy technique analysis confirms the presence of the Fe3+- complexes in octahedral coordination. The new heterogeneous catalysts were catalytic evaluated by phenol hydroxylation and compared with the encapsulated metal furanyl-azine complexes in NaY zeolite. The zeolite themselves do not present any activity and the presence of the metal complexes improve their activity. All heterogeneous catalysts enhance higher conversion of phenol to catechol.Graphical abstractImage 1
       
  • Accuracy of semiexperimental equilibrium structures: Sulfine as an example
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Jean Demaison, Natalja Vogt, Denis N. KsenafontovThe Born-Oppenheimer ab initio equilibrium structure of sulfine, CH2SO, was computed at the CCSD(T) level of theory using basis sets up to quintuple zeta quality. The semiexperimental equilibrium structure was also determined from the ground state rotational constants and different anharmonic force fields. The factors affecting the accuracy and the precision of this semiexperimental structure were investigated. It was found that the accuracy of the structure, contrary to its precision (i.e. the standard deviations of the structural parameters), is not sensitive to the quality of the force field (B3LYP, B2PLYPD3 and MP2) and to neglecting of the centrifugal or electronic corrections.Graphical abstractImage 1
       
  • Structural, spectral and biological investigations on Cu(II) and Zn(II)
           complexes derived from NNO donor tridentate Schiff base: Crystal structure
           of a 1D Cu(II) coordination polymer
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Manjari Jayendran, P.M. Sabura Begum, M.R. Prathapachandra KurupCopper(II) and zinc(II) complexes of an NNO donor tridentate Schiff base, 4-bromo-2-(((3-(methylamino)propyl)imino)methyl)phenol (HL), were synthesised and characterized by different physicochemical methods including single crystal XRD, elemental analysis, IR, electronic and EPR spectral analysis. Copper(II) complex is a 1D coordination polymer in which chlorine acts as a bridging ligand and zinc(II) complex is a bis-ligated one. Hirshfeld surface analysis of the complexes has been carried out which provided better understanding of intermolecular interactions. Effects of solvents on charge transfer bands and d-d bands were investigated and the former shows a negative solvatochromic behaviour and latter a positive behaviour upon increasing solvent polarity. Luminescent properties were analysed and found that copper(II) and zinc(II) complexes exhibit quenching and enhancement of fluorescence respectively which is backed by quantum yield values. Cytotoxic activity of both complexes has been screened in vitro against lymphoma ascites cell lines. In addition, antibacterial activity of complexes has been screened against bacterial species Bacillus cereus, Staphylococcus aureus, Klebsiella pneumonia and Escherichia coli.Graphical abstractImage 1
       
  • A novel dibenzimidazole-based fluorescent organic molecule as a turn-off
           fluorescent probe for Cr3+ ion with high sensitivity and quick response
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Aiyun Zhu, Jie Pan, Yan Liu, Feng Chen, Xinxin Ban, Suyu Qiu, Yuhui Luo, Qingzheng Zhu, Jianmin Yu, Weiwei LiuDue to the toxicity and ubiquity of chromium contamination, fluorometric detection of chromium ions (Cr3+) has attracted much attention. Here, a new fluorescent probe 4PBI-Cz based on novel dibenzimidazole group was designed and synthesized to identify chromium ions. The photophysical and electrochemical properties of 4PBI-Cz were characterized in detail. In view of the strong complexation property, the fluorescence of 4PBI-Cz exhibit gradually turn-off phenomenon with the addition of chromium ions. In particular, the response time of the probe with chromium ions was less than 1 s, faster than most of the reported fluorescence probes. Moreover, the detection limit for chromium ions is only 3.5 nM, which can be attributed to the high sensibility of dibenzimidazole to the ions. This research indicates that the new proposed dibenzimidazole group is an exciting recognition receptor for designing quick response and ultrasensitive fluorescent probes for the determination of Cr3+.Graphical abstractThe dibenzimidazole based fluorescent probe exhibited strong blue luminescence and further showed sensitive turn-off fluorescence response to Cr3+ ion.Image 1
       
  • Investigation of electrical conductance properties, non-covalent
           interactions and TDDFT calculation of a newly synthesized copper(II) metal
           complex
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Samit Pramanik, Saugata Konar, Koushik Chakraborty, Tanusri Pal, Sourav Das, Sudipta Chatterjee, Malay Dolai, Sudipta PathakAbstract[Cu(pydc)(apy)]·3H2O (1) (pydcH2 = pyridine-2,6-dicarboxylic acid; apy = 2- aminopyridine) has been synthesized and characterized by elemental analysis, IR spectroscopy and single crystal X-ray diffraction techniques. Crystallographic analysis tells that the complex 1 has distorted square pyramid geometry with pydcH2 coordinated as a tridentate ligand to each metal ion through two oxygen atoms of each carboxylate group and the nitrogen atom of the pyridine moiety. Three non-coordinated water molecules are present in the asymmetric unit and all are involved in constructing a (H2O)6 cluster with chair conformation like cyclohexane. Interestingly, The average O⋯O distance of 2.759 Å in water hexamer of Complex 1 is closer to the respective distance of ice (2.76 Å for ice Ih at 90 K) than to that of bulk liquid water (2.85 Å). Also, the average O–O–O bond angle of 107.96° is close to the tetrahedral angle in ice Ih form. Apart from water cluster, the aromatic molecules are engaged in several non-covalent interactions like NH … π, lone pair … π, π … π and hydrogen bonds. These types of non-covalent interactions attribute to the supramolecular framework of the studied molecule. The electrical conductivity in terms of current was measured at room temperature before and after annealed of the synthesized complex compound on thin film specimen of order 230 and 240 μA respectively with bias voltage 1 V. In addition, the electronic transitions of 1 were recorded and the electronic distribution of HOMO-LUMO was rationalized theoretically (through time-dependent density functional theory (TDDFT)).
       
  • Palladium (II) complexes containing substituted thiosemicarbazones.
           Synthesis, spectral characterization, X-ray crystallography, biomolecular
           interactions and in vitro cytotoxicity
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): D. Anu, P. Naveen, Nigam P. Rath, M.V. KaveriPalladium (II) complexes were synthesized from 4(N)-substituted thosemicarbazones schiff base ligands. The new complexes were confirmed by analytical, various spectroscopic techniques and single crystal X-ray crystallography. Crystallographic studies exhibited that the complexes 2 and 3 distorted square planar geometry around palladium metal ion. All the complexes are proved their DNA/protein binding ability by using absorption and emission titrations. Investigations of antioxidant properties showed that all the complexes have significant radical scavenging properties. The anticancer activity of Pd(II) complexes was probed in vitro cytotoxicity against human breast (MCF7) and lung (A549) cancer cell lines by MTT assay. Further, AO/EB and DAPI staining methods were carried out to detect the cell death induced by the complexes. Among all the complexes, complex 1 exhibited better cytotoxic activity.Graphical abstractImage 1
       
  • Syntheses and electron density distribution studies in two new imidazole
           derivatives
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Maharzadi Noureen Shahi, Alia Iqbal, Rashida Bibi, Misbah-ul-Ain Khan, Maqsood Ahmed, Sajida NoureenAbstractImidazole derivatives find wide scale and diverse applications. In this work two new imidazole based compounds have been synthesized. Their structures were confirmed using NMR, Mass Spectrometry and IR techniques. In addition, three dimensional structures were elucidated using single crystal X-rays diffraction analysis. The structures were refined using the classical independent atom model and the aspherical pseudo-atom model from an electron density database. The electrostatic properties and the topology of covalent bonds and intermolecular interactions of both the molecules were quantified on the basis of transferred electron density parameters. This study encourages the use of transferability principle for routine structure analysis as it gives better refinement statistics and reliable estimation of chemical reactivity through the study of electrostatic properties.
       
  • Adsorption of ciprofloxacin hydrochloride on multiwall carbon nanotube
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Ayça Avcı, İsmail İnci, Nilay BaylanAbstractCiprofloxacin hydrochloride is an important pharmaceutical ingredient. It is used for many bacterial infection treatment. It can present in water sources due to incomplete metabolism in humans and coming from the pharmaceutical factory effluents. In this work, the adsorption of ciprofloxacin hydrochloride by multiwall carbon nanotube (MWCNT) was investigated. The effects of equilibrium of adsorption time and initial ciprofloxacin hydrochloride concentration on adsorption were determined. Langmuir and Freundlich isotherm models were utilized to express to the adsorption mechanism of ciprofloxacin hydrochloride by MWCNT. In addition, pseudo-first order, pseudo-second order and Elovich kinetic models were applied. This study showed that MWCNT absorbent is highly effective adsorbent for the removal of ciprofloxacin hydrochloride from aqueous solutions. Equilibrium data for adsorption of ciprofloxacin hydrochloride on MWCNT were best exemplified by Freundlich isotherm with a value of R square 0.9993. The most favorable kinetic model was obtained as pseudo-second order kinetic model with a value of R square 1.000.
       
  • Mössbauer and EPR study of ferrihydrite and siderite biotransformations
           by a syntrophic culture of alkaliphilic bacteria
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Angelina Antonova, Nataliya Chistyakova, Maria Gracheva, Vyacheslav Rusakov, Yury Koksharov, Tatyana Zhilina, Daria ZavarzinaAbstractTransformations of iron-containing minerals − synthesized ferrihydrite and natural siderite performed by a syntrophic co-culture of Candidatus “Contubernalis alkalaceticum” and Geoalkalibacter ferrihydriticus in presence of ethanol as the substrate for the obligate syntroph – were studied by 57Fe Mössbauer and EPR spectroscopic techniques. Mössbauer spectra of solid phase samples were collected in the range of temperatures 5.5–300 K. X-band EPR studies were carried out at room temperature. The formation of a mixture of magnetite and maghemite, siderite and iron oxyhydroxycarbonate was found as the result of biogenic transformations of synthesized ferrihydrite. In the case of siderite, the formation of a mixture of magnetite and maghemite and iron oxyhydroxycarbonate was observed.
       
  • Comparative analysis of upconversion emission of LaF3:Er/Yb and LaOF:Er/Yb
           for temperature sensing
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Huanjun Zhang, Xingbang Dong, Liying Jiang, Yang Yang, Xuerui Cheng, Hongmei ZhaoAbstractUp-conversion (UC) luminescence of Er3+ greatly depends on the host matrix. In the present study, the comparison of UC emission from Er3+ is investigated by varying host matrix, including hexagonal LaF3, rhombohedral (R-) and tetragonal (T-) LaOF. The tetragonal LaOF:Er/Yb exhibits the most intensive emission under the same condition. Instead of phonon threshold and phase structure, local field symmetry after doping is the main reason for its luminescence enhancement. T-LaOF:Er/Yb is selected as the candidate for temperature sensing. The pump power dependent UC emission and optical temperature sensing properties of T-LaOF:Yb/Er are investigated. The results suggest that T-LaOF:Er/Yb not only exhibit more intense emission, but also has higher sensitivity. Its maximum sensitivity is 3.5‰ K−1 around 400 K, suggesting it is a potential candidate in temperature sensing.
       
  • Evaluation of corrosion inhibition of 4-(pyridin-3-yl) thiazol-2-amine for
           copper in HCl by experimental and theoretical studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Razieh Farahati, Hadi Behzadi, S. Morteza Mousavi-Khoshdel, Ali GhaffarinejadThis study investigates the effect of corrosion inhibition of 4-(pyridin-3-yl) thiazol-2-amine (PyTA) on the copper surface. The inhibition efficiencies were evaluated by a series of techniques such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, scanning electron microscopy (SEM), and atomic force microscopy (AFM) in various inhibitory concentrations in 1 M HCl solution. The results showed that PyTA can be an effective corrosion inhibitor of copper in an acid solution. According to the EIS approach, the maximum inhibition efficiency (IE%) of 94% is achievable at 1 mM concentration. The adsorption of inhibitor obeyed Langmuir adsorption isotherm. Theoretical studies, namely molecular dynamics (MD) simulation and density functional theory (DFT), were also performed. A comparison of corrosion inhibition of PyTA with our previous work showed that PyTA offers better corrosion protection.Graphical abstractImage 1
       
  • d-glucose,+KCl·2C6H12O6&rft.title=Journal+of+Molecular+Structure&rft.issn=0022-2860&rft.date=&rft.volume=">Sugar-metal ion interaction: Crystal structure and spectroscopic study of
           potassium chloride complex with d-glucose, KCl·2C6H12O6
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Xiao-Yan Kang, Ye-Di Chang, Jing-Dan Wang, Li-Min Yang, Yi-Zhuang Xu, Guo-Zhong Zhao, Shuai Li, Ke-Xin Liu, Jia-Er Chen, Jin-Guang WuPotassium ion plays an important role in a variety of bioactivities, and many functions of potassium ion are exerted via coordination with saccharides. Up to now, the understanding of the biochemistry of K+/saccharides system is limited due to the lack of crystal structures of potassium ion-saccharide complexes. Herein, we have prepared single crystal of potassium chloride-α-d-glucose complex (KCl·2C6H12O6) and its crystal structure has been successfully obtained. Potassium ion is coordinated to two α-d-glucose molecules. One α-d-glucose molecule provides 4α and 6β hydroxyl groups to coordinate to potassium ion, another one uses its 2α and 3β hydroxyl groups to coordinate to potassium ion. The single crystal structure of the complex exhibits some unusual structural features. K⋯K dimer is suggested to form because of shorter K⋯K distance (3.059 Å). Moreover, unusually short O⋯Cl distances between 2.3 and 2.5 Å are found in the crystal. Based on the crystal structure of the complex and the fact no free OH stretching vibrational absorption band is observed in FTIR spectra of the complex, assignment of hydrogen bonding linkage is achieved. Coordination with potassium ion brings about considerable structure variation on the glucose moiety of the complex. The structural changes can be reflected in the corresponding FTIR, Raman, FIR and THz spectra.Graphical abstractImage 1064
       
  • Corrigendum to “Carbonate substitution in lead hydroxyapatite
           Pb5(PO4)3OH” [J. Mol. Struct. 1147 (2017) 594–602]
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): M. Kwaśniak-Kominek, M. Manecki, J. Matusik, M. Lempart
       
  • Triorganotin(IV) complexes of Schiff base derived from 1,2,4-triazole
           moiety: Synthesis, spectroscopic investigation, DFT studies, antifungal
           activity and molecular docking studies
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Rachana Joshi, Ankita Kumari, Karuna Singh, Hirdyesh Mishra, Sandeep PokhariaNew triorganotin (IV) complexes of Schiff base (E)-4-amino-3-(2-(4-hydroxybenzylidene)hydrazinyl)-1H-1,2,4-triazole-5(4H)-thione (HL) with general formula R3SnL (where L is the monoanion of Schiff base (HL) and R = n-Bu(1)/Ph(2)) have been synthesized and thoroughly characterized by using analytical and multi-spectroscopic techniques such as FT-IR/Raman, NMR (1H, 13C, 119Sn), 2D-HMQC, ESI-MS spectrometry. A distorted tetrahedral geometry around tin have been proposed for these organotin (IV) derivatives in which Schiff base ligand acts as monoanionic monodentate coordinating through the Ohydroxyl. A density functional theory (DFT) based quantum chemical calculations have been performed at B3LYP/6-31G (d,p)/Def2-SVP(Sn) level of theory. The atomic charges have been calculated at the selected atoms, and the reactive sites have been assigned on the surface of the molecules through molecular electrostatic potential (MEP) map. In order to obtain an insight into the structure and reactivity behaviour, the conceptual-DFT based global and local reactivity descriptors and the frontier molecular orbital analysis was carried out to study the charge transfer within the complex. A comparative analysis of calculated vibrational frequencies with experimental vibrational frequencies was carried out and significant bands were assigned. The nature of O–Sn bonding is discussed in terms of the natural bond orbital (NBO) analysis. In vitro antifungal activity of the triorganotin (IV) complexes and Schiff base ligand were tested to explore their potential antifungal activity and the obtained bioactivity results were further validated by in Silico molecular docking studies.Graphical abstractImage 1
       
  • A hybrid molecular rotor crystal with dielectric relaxation and
           thermochromic luminescence
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Mei Shi, Shan-Shan Yu, Hui Zhang, Shao-Xian Liu, Hai-Bao DuanHerein, we reported a hybrid crystals, [C3-Mim][PbBr3] (1) where C3-Mim+ = 1-propyl-3-methylimidazolium, this compound shows two steps solid-solid phase transition at 256 and 359 K, respectively. The first phase transition is related to the strong thermal vibrations of the crystal lattice, and the alkyl chain rotation motion on a single axis of organic cations can be observed from the temperature dependent crystal structure. The second step phase transition were proved by temperature dependent powder X-ray diffraction and accompanied by remarkable dielectric relaxation. In addition, the temperature-dependent photoluminescent indicated two emission bands from organic and inorganic component have different sensitivity to temperature, leading to 1 showing photoluminescent thermochromism, which may have potential application in the thermosensitive devices.Graphical abstractImage 1
       
  • Synthesis and characterization of Co-Al mixed oxide nanoparticles via
           thermal decomposition route of layered double hydroxide
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): M.H. Abdel-Aziz, M. Sh. Zoromba, M. Bassyouni, M. Zwawi, A.A. Alshehri, A.F. Al-HossainyAbstractCobalt-aluminum layered double hydroxide (Co-Al LDH) is synthesized in the presence of functional amino-organic compounds, including glycine, acetamide and urea. Mixed cobalt-aluminum oxide nanoparticles were prepared from Co-Al LDH by the calcination method. The mixed oxides nanoparticles are characterized by a number of diverse techniques such as FTIR, TGA, XRD, SEM and TEM. The presence of functional amino-organic compounds affects the XRD patterns of Co-Al LDH and the computed lattice parameters. Thin films from Co-Al LDHs with 100 ± 5 nm thickness were fabricated by thermal evaporation method. The average optical energy gaps for Co-Al LDHs films were 2.325 eV with the optical characterization ratio of σ2:σ1 and ε1:ε2 resulted from thin film. Based on the obtained results mixed Co-Al oxides nanoparticles are considered promising alternative materials for producing clean and renewable energy and for enhancing the power conversion efficiency of the prototype of solar cell.
       
  • Electrochemistry, electropolymerization and electrochromism of novel
           phthalocyanines bearing morpholine groups
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Duygu Akyüz, Ümit Demirbaş, Atıf Koca, Fatih Çelik, Halit KantekinAbstractIn this work, 4-(4-((4-morpholinophenylimino)methyl)phenoxy)phthalonitrile (3) and it’s peripherally tetra substituted metal-free (4), zinc(II) (5), copper(II) (6) and nickel(II) (7) phthalocyanines were synthesized for the first time. The structural characterization of these novel compounds were performed with FT-IR, 1H NMR, 13C NMR, UV–Vis and mass spectroscopy. Electrochemical and spectroelectrochemical characterizations of phthalocyanines (4–7) showed that while all phthalocyanines went to characteristics phthalocyanine ring and/or metal based reduction processes during the negative potential scans, all complexes were coated on the working electrode during the oxidation processes due to the cationic electropolymerizations of the 4-(4-((4-morpholinophenylimino)methyl)phenoxy) substituents. Changing the metal centers of phthalocyanine ring influenced the redox processes due to the different redox activities and effective nuclear charges of the metal centers. In addition to the electropolymerization ability of 4-(4-((4-morpholinophenylimino)methyl)phenoxy) substituent slightly affected the reversibility and peak positions of the redox processes. Indium tin oxide coated glass electrode (ITO) was coated with electropolymerized films of phthalocyanines to construct ITO/Poly-Phthalocyanine and these electrodes were tested as a potential electrochromic material. ITO/Poly-Phthalocyanine provided color change between green and blue with 1.2 s switching time, 18% optical contrast and 100% optical stability with 50 cronoamperometric (CA) cycles. These studies indicated possible usage of the electropolymerized films of phthalocyanines as possible building blocks for advanced electrochromic devices needing green-blue color change.
       
  • Palladium-carbene catalyzed direct arylation of five-membered
           heteroaromatics
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Murat Kaloğlu, Nazan Kaloğlu, İlkay Yıldırım, Namık Özdemir, İsmail ÖzdemirAbstractDue to the industrial importance of bi(hetero)arenes, the synthesis of these compounds by homogeneous Pd-catalyzed direct arylation is an important research topic in modern organic chemistry. In this study, PEPPSI-type, (PEPPSI = Pyridine Enhanced Precatalyst Preparation Stabilization and Initiation), new Pd-catalysts with N-heterocyclic carbene ligand were synthesized, and they were used as catalysts in the synthesis of bi(hetero)arenes by direct arylation process. The structures of Pd-carbene complexes were elucidated by different spectroscopic and analytical techniques such as NMR, FT-IR and elemental analysis. The more detailed structural characterization of one of the complexes was determined by single-crystal X-ray diffraction study. Pd-carbene complexes were used as effective catalysts in the direct arylation of five-membered heteroaromatics such as thiophene, furan and thiazole derivatives with (hetero)aryl bromides for 1 h, in the presence of 1 mol% of catalyst loading, and successful results were obtained.
       
  • Enhanced performance of dye-sensitized solar cells based on a dual
           anchored diphenylpyranylidene dye and N719 co-sensitization
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Xinxin Wang, Altan Bolag, Wu Yun, Yanqing Du, Chaolu Eerdun, Xiaoying Zhang, Tana Bao, Jun Ning, Hexig Alata, Tegus OjiyedAbstractTo explore the co-sensitizing ability of 2,6-diphenyl-4H-pyranylidene (DP) dye, a novel dye W2 with dual anchor was synthesized, characterized and studied for the application of dye-sensitized solar cells. The results showed that the power conversion efficiency of W2 achieved 4.77% and further improved to 5.56% with 30 mM of chenodeoxycholic acid added as co-absorbent. Solar cell based on N719 + W2 co-sensitization system exhibited enhanced photocurrent than the reference N719 dye, promoting the power conversion efficiency from 7.77% to 8.20% and enhanced to 8.49% in presence of co-absorbent. These elevated superior performance resulted mainly from a there higher molar extinction coefficient of dye W2 in range of 325–475 nm complementing the light-harvest ability of N719 dye.
       
  • Thermal stability, degradation kinetic and structural characterization of
           novel aromatic amide compounds
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Dilek ÇanakçıAbstractIn this study, six novel amide compounds with three different structures were synthesized. At the beginning of the study, two novel amide compounds were formed using 3,7-Dihydroxy-2-naphthoic acid, 2-Amino-5-methylphenol and 2-Amino-3-chloro-phenol as basic materials. Then, the polymerization of the synthesized amide compounds were conducted with oxidative polycondensation method in which NaOCl was used as oxidant. Finally, copper complexes were synthesized using polymers as ligand. All synthesized compounds have been characterized by IR, UV–vis and H NMR spectral studies, LC-MS and GPC chromatographic studies, and SEM analysis. Thermal stabilities of amide monomers, polymers and copper complexes were determined by TGA technique. Furthermore, thermodynamic parameters of the degradation process were determined for all synthesized compounds with the use of non-isothermal method: Flynn-Wall-Ozawa method. The variation of the heating rate at TGA technique has allowed us to investigate and discuss the influence of different heating rates on decomposition of the compounds.
       
  • Computational screening of promising beta-secretase 1 inhibitors through
           multi-step molecular docking and molecular dynamics simulations -
           Pharmacoinformatics approach
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Shruti Gupta, Devendra Parihar, Mokshada Shah, Shivali Yadav, Husain Managori, Shovonlal Bhowmick, Preeti Chunarkar Patil, Siham A. Alissa, Saikh Mohammad Wabaidur, Md Ataul IslamAlzheimer’s disease (AD) is a neurodegenerative disorder generally developed with aging. AD slowly hammers the memory and cognitive abilities which eventually leads to abnormal behaviour, and ultimately left with disability and dependency. It is anticipated that by the year 2050, world population will experience the incidence of 100 million AD cases. It has been more than hundred years passed since AD recognized as a dreadfull disease, but there is no effective curative agent discovered against AD to date. One of the major hallmarks of the AD development is the accumulation of extracellular amyloid-beta (Aβ) plaques in the brain. In the amyloidogenic process, an extensively studied beta-secretase enzyme, known as BACE1, plays a key role in the accumulation and production of Aβ fragments. Therefore, successful inhibition of BACE1 by small molecular chemical entities can be an effective approach for anti-AD drug development. Hence, the current study has been perceived to find out potential BACE1 inhibitiors by virtual screening of entire Asinex chemical library database through multi-step molecular docking methodologies. Further, sequential screening of in-silico pharmacokinetics, molecular dynamic (MD) simulations analyses along with binding free energy estimation were performed. Comparative analyses and characteristics of molecular binding interactions assessment finally suggests that five molecules (B1–B5) to be the most promising BACE1 inhibitors. Molecular interactions analyses revealed that either one or both the catalytic dyad residues (Asp32 and Asp228) of BACE1 has formed strong molecular interactions with all the proposed molecules. Not only the catalytic dyad residues are involved in the formation of molecular binding interactions but also other important non-Asp binders residues such as Gly34, Tyr71, Trp115, Arg128, Lys224, Gly230, Thr231, Thr232, Arg235, Thr329, and Val332 found to interact with the selected compounds. Moreover, the dynamic behaviour of proposed molecules and BACE1 was explored through all-atoms MD simulation study for 100 ns time span. Analysis of MD simulation trajectories explained that all identified molecules are efficient enough to retain the structural and molecular interactions integrity inside the receptor cavity of BACE1 in dynamic environment. Finally, the binding free energy of each molecule has calculated from MD simulation trajectories through MM-PBSA method and found that all molecules possess a strong binding affinity towards the BACE1. The high negative binding free energies are found to be within the range of −994.978 to −561.562 kJ/mol for the identified compounds. Henceforth, analyses of extensively studied multi-cheminformatics approaches explained that proposed molecules might be promising BACE1 inhibitors for therapeutic application in AD, subjected to experimental validation.Graphical abstractImage 1
       
  • Synthesis, characterization and biological assay of three new
           benzotriazole-based Zn(II) complexes
    • Abstract: Publication date: 15 April 2020Source: Journal of Molecular Structure, Volume 1206Author(s): Ning Ling, Xia Wang, Dai Zeng, Ya-Wen Zhang, Xiang Fang, Huai-Xia YangThree new Zn(II) complexes, namely [Zn(emimb)2Cl2] (1), [Zn(dmimb)2Cl2] (2) and [Zn(bmem)2(SCN)2] (3), have been synthesized using the benzotriazole-based ligands, 1-((2-ethyl-4-methyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (emimb), 1-((2,4-dimethyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (dmimb) and 1-((2-ethyl-1H-imidazol-1-yl)methyl)-1H-benzotriazole (bmem). All the complexes were fully characterized by elemental analysis, IR spectroscopy, 1H NMR spectroscopy and single-crystal X-ray diffraction analysis. Complexes 1–3 show mononuclear structures and the central Zn(II) ion of 1–3 is four-coordinated in a distorted tetrahedral coordination geometry. Complex 2 presents an interesting 3-D network through two different intermolecular π-π stacking interactions. The antidiabetic activities against α-amylase of ligands and complexes 1–3 are investigated in vitro. The results indicate that the three Zn(II) complexes inhibit α-amylase more strongly than free ligands. Antioxidant tests in vitro show that the complex 3 possesses a mild antioxidant activity against 1,1-diphenyl-picrylhydrazyl (DPPH). In addition, the solid-state photoluminescence properties of ligands and their Zn(II) complexes have been investigated.Graphical abstractImage 1
       
  • Novel substituted aniline based heterocyclic dispersed azo dyes coupling
           with 5-methyl-2-(6-methyl-1, 3-benzothiazol-2-yl)-2,
           4-dihydro-3H-pyrazol-3-one: Synthesis, structural, computational and
           biological studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): M.R. Maliyappa, J. Keshavayya, N.M. Mallikarjuna, I. PushpavathiAbstractIn this study, we have synthesized four heterocyclic azo dyes by conventional diazo-coupling reaction between aniline derivatives with 5-methyl-2-(6-methyl-1,3-benzothiazol-2-yl)-2,4-dihydro-3H-pyrazol-3-one at lower temperatures and are characterized by physico-chemical techniques. The quantum chemical study was also employed to understand the chemical reactivity of the compounds by using B3LYP method in conjunction with 6–31G (d, p) basis set. The photochemical property of the dyes was studied and they showed higher intensity and good quantum yield with respect to the Rhodamine B. The azo dyes were screened for their antimycobacterial activity against M. tuberculosis and the results showed appreciable antitubercular activity. The anticancer activity of the compounds was studied against HCT116, A549, Jurkat and K562 and all the compounds could be able to inhibit the growth of the cancerous cells.
       
  • Regioselective N-alkylation of some imidazole-containing heterocycles and
           their in vitro anticancer evaluation
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Cigdem Karaaslan, Fatima Doganc, Mehmet Alp, Asli Koc, Arzu Zeynep Karabay, Hakan GökerImidazole-containing heterocycles: Imidazopyridines, imidazopyrimidines and imidazopyra-zines can exist more tautomeric forms than benzimidazoles. Their regioselectivities were determined for N-alkylations with 4-fluorobenzyl bromide under basic conditions (K2CO3) in DMF. We observed that, regioisomers were mainly formed as a mixture in this reaction and N-benzylation occurs at a higher ratio on six membered heterocycles. Their structural assignments were made with the use of two-dimensional 1H–1H NOE (nuclear overhauser effect spectroscopy, NOESY). Complementary structural information was provided by 2D-HMBC spectra of the compounds. Synthesized compounds were tested for in vitro cytotoxic activities against Human colon cancer cell line (HCT-116) and leukemia cell lines (K562 and HL-60) by MTT test. Among them, imidazopyridine analogue 10, bearing bromine atom at the C-6 position of the pyridine moiety, gave the lowest IC50 value with 6–7 μg/mL against all three cancer cell lines.Graphical abstractN-Benzylation of 2-substitutedimidazo[4,5-c]pyrimidine (purine).Image 1
       
  • 2,2’:6’,2’’-Terpyridine derivative with tetrazole motif and its
           analogues with 2-pyrazinyl or 2-thiazolyl substituents – Experimental
           and theoretical investigations
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Dawid Zych, Aneta Slodek, Jan Grzegorz MałeckiThe synthesis of 4’-[4-(2-decyl-1,3,4-tetrazol-5-yl)phenyl]-2,2’:6’,2’’-terpyridine and its analogues which contain substituted at the central pyridine ring (positions 2 and 6) 2-pyrazinyl or 2-thiazolyl groups is reported. Photophysical, optical studies and theoretical calculations analysis with particular emphasis on the difference caused by the change of substituents is presented.Graphical abstractImage 1
       
  • A choline chloride-based deep eutectic solvent promoted three-component
           synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d] pyrimidinone
           (thione) derivatives
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Mohammad Biglari, Farhad Shirini, Nosrat O. Mahmoodi, Mehdi Zabihzadeh, Maryam MashhadinezhadAn efficient one-pot method for the synthesis of tetrahydrobenzo[b]pyran and pyrano[2,3-d]pyrimidinone (thione) derivatives through a three-component reaction between aldehydes, malononitrile and enolizable C–H activated acidic compounds using a new deep eutectic solvent made of choline chloride, urea and thiourea as an environmentally benign catalyst has been reported. The structure of the catalyst was characterized using FT-IR, 1H NMR, and 13C NMR. The present method exhibits some notable advantages such as ease of the preparation and handling of the catalyst, low cost, green reaction conditions, short reaction times, high yields, and simple work-up. Also, the catalyst could be recovered easily and recycled up to four times without significant loss of catalytic activity.Graphical abstractImage 10559
       
  • The microwave spectrum and structure of 2-ethynylthiophene
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Yan Jin, Tao Lu, Qian Gou, Gang FengAbstractThe microwave spectroscopic and theoretical investigation of the 2-ethynylthiophene was carried out. Rotational spectra of eight isotopologues in their natural abundance were measured and assigned, which allowed a precisely structural determination. The substituent effect on the π-electron distribution was revealed by comparing the molecular electrostatic surface potentials of thiophene, 2-chlorothiophene and 2-ethynylthiophene.
       
  • A comprehensive DFT study of the molecular structures of (6, 3) chiral
           carbon nanotubes doped with the elements of groups III and V
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Behnam Dehbandi, Mohammad Reza Zardoost, Zohreh Mirjafary, Zinattosadat HossainiThe electronic, structural and physical properties such as bond length, angles, total energy, dipole moments, Mulliken atomic charges, formation energy, NMR parameters, DOS-PDOS, NBO, QTAIM analysis of chiral (6, 3) carbon nanotubes (CNTs) and their doped structures with the elements of groups III and V have been investigated by density functional theory. The calculations indicated that the average bond lengths increased from up to down in the groups. In and Sb atoms considerably reduce the band gap of CNTs. The dipole moments of doped (6, 3) chiral CNTs show fairly large changes with respect to the pristine model.Graphical abstractImage 103676
       
  • Molecular structure of 1,4-bis(substituted-carbonyl)benzene: A combined
           experimental and theoretical approach
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Ezzat Khan, Muhammad Khalid, Zarif Gul, Adnan Shahzad, Muhammad Nawaz Tahir, Hafiz Muhammad Asif, Sumreen Asim, Ataualpa Albert Carmo BragaThe reaction of pyrazole derivatives (pyrazole (Pz), 3-methylpyrazole (MPz) and 3,5-dimethylpyrazole (DMPz)) with terephthaloyl dichloride (TD) in the presence of Et3N afforded the desired products, 1,4-bis(pyrazolylcarbonyl)benzene (1), 1,4-bis(3-methylpyrazolylcarbonyl)benzene (2) and 1,4-bis(3,5-dimethylpyrazolylcarbonyl)benzene (3).Good quality crystals were isolated and diffraction data for single crystal were collected which revealed that compounds 1–3 are monoclinic with space group P21/n, C2/c and P21/c, respectively. These compounds were obtained as a result of C–N coupling reaction between the acid chloride and pyrazol derivatives with the intent to explore their structure in solution as well as solid state. Density function theory (DFT) calculations using B3LYP and CAM-B3LYP functionals with 6-311G(d,p) basis set were performed to explore geometric and electronic properties of compounds. The Root Mean Square Error (RMSE) has also been calculated for the values of geometric parameters, indicating a good agreement with experimental findings. Moreover, frontier molecular orbitals (FMOs) and natural bond orbitals (NBOs) analyses were carried out through B3LYP/6-311G(d,p) level of theory. The linear polarizability (α) values of nonlinear optical (NLO) analysis were calculated with the same level of theory and basis set as FMO but under different solvent conditions. Time Dependent Density Functional Theory (TD-DFT) study of these pyrazole substituted derivatives was performed aiming to investigate UV–Visible behavior. The stability of molecule has been additionally analyzed by Hirshfeld surface analysis in addition to NBO analysis. The calculated HOMO and LUMO energies from FMO assisted in calculating global reactivity parameters (Chemical hardness, chemical softness, electronegativity, EA, IP and electrophilicity). Natural population analysis (NPA) and Molecular electrostatic potential (MEP) were also performed to obtain insights about the reactivity of compounds 1–3. Theoretical calculations indicate that these compounds have considerable low reactivity and can be used for development of coordination chemistry under optimum conditions.Graphical abstractThe Reaction between terephthaloyl dichloride and 2-aminopyrazol derivatives give corresponding compounds 1,4-phenylenebis(1H-pyrazol-1-yl)methanone (1), 1,4-phenylenebis(3-methyl-1H-pyrazol-1-yl)methanone (2) and 1,4-phenylenebis(3,5-dimethyl-1H-pyrazol-1-yl)methanone (3). All compounds are crystalline and their structures were confirmed by single crystal X-ray diffraction. Detailed DFT calculations for compounds were also carried out.Image 1
       
  • Sensitive voltammetric sensor based on silver dendrites decorated
           polythiophene nanocomposite: Selective determination of L-Tryptophan
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): S. Dheepthi GunaVathana, P. Thivya, J. Wilson, A. Cyrac PeterAbstractThis present work describes the direct electrochemical determination of L-Tryptophan (L-Try) using polythiophene (PT) with silver (Ag) dendrites composite formed via electrostatic interaction. In the composite, Ag dendrites provide the energy to speedup chemical reaction by the presence of cationic free radicals and found attached with the backbone of PT. Furthermore, the sulfur groups of PT help in the formation of a stable product, and keeping them in same phase. The PT-Ag modified Glassy Carbon Electrode (GCE) revealed excellent electrochemical activity towards the oxidation of L-Try with the linear response in the concentration range of 200 nM–400 μM with detection limit of 20 nM. The fabricated sensor demonstrated the selective determination of L-Try in presence of foreign substances and the PT-Ag modified interface lead to the development of novel biosensor with high sensitivity and good stability which is mainly attributable to increased surface area of the composite. The characteristics of the PT-Ag hybrid nanocomposite proved the determination of L-Try in real food samples like soybeans extract with satisfactory results.
       
  • Synthesis, crystal structure, Hirshfeld surface analysis and DFT
           calculations of
           
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Mustafa R. Albayati, Sevgi Kansız, Necmi Dege, Savaş Kaya, Riadh Marzouki, Hassane Lgaz, Rachid Salghi, Ismat H. Ali, Majed M. Alghamdi, Ill-Min ChungHydrazones are an important class of organic compounds, which exhibit large pharmacological applications. Hydrazones have long been used for the synthesis of a wide range of useful heterocyclic compounds due to their reactivity toward electrophiles and nucleophiles. Herein, a hydrazone derivative, 2-[(2,3-dimethylphenyl)amino]-N’-[(E)-thiophen-2-ylmethylidene]benzohydrazide, noted C20H19N3OS was synthesized and its three-dimensional structure was determined by X-ray crystallography. Structural characterization by X-ray crystallography was supported by Density Functional Theory (DFT) calculations. Intermolecular interactions in the crystal network were determined using Hirshfeld surface analyses. The optimized geometry, global reactivity descriptors, Natural Bond Orbital (NBO) analysis, and HOMO-LUMO orbitals of the molecule were computed using the DFT-B3LYP method and 6–311++G (d,p) basis set. C20H19N3OS has a monoclinic system and P21/c space group with parameters a = 13.9774 (13) Å, b = 16.3851 (16) Å, c = 8.2101 (8) Å, β = 105.429 (7)° and Z = 4. C20H19N3OS forms an S (6) ring motif with an intramolecular N–H⋯O hydrogen bond. In the crystal, the molecule chains along the c-axis direction are linked by C–H⋯O hydrogen bond. Atomic charges were predicted using the Mulliken population and the NBO theory. The molecular electrostatic potential (MEP) picture was drawn using the same level of theory to visualize the chemical reactivity and charge distribution on the molecule. The local reactivity was examined by determining the Fukui functions and dual descriptor indices.Graphical abstractImage 1
       
  • The sequence of changes observed during degradation process of paper by
           the use of UV/VIS and FTIR spectrometry with application of the PCA and 2D
           correlation method for forensic purposes
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): J. Zięba-Palus, B. Trzcińska, A. Wesełucha-Birczyńska, P. Moskal, J. SacharzAs paper is the base for (printed) documents-including bogus documents-it is often the subject of forensic investigations. Its properties depend on interactions between and within cellulose chains, mainly assigned to inter-and intramolecular hydrogen bonds. During paper degradation, the degree of polymerization of the cellulose chain changes. Vibrational spectroscopy has already been widely applied to resolve cellulose structure, crystalline phases and hydrogen bonds networks. The aim of the present research was to evaluate the possibility of differentiating between degraded papers by spectroscopic techniques.Five paper samples were artificially aged in a climatic chamber under 65% relative humidity in air at 90 °C for various periods up to 35 days. The conditioned samples – of differing durations of ageing – were then analyzed using infrared and UV/VIS spectroscopy.It was observed that the paper samples differed in the range 1000–1120 cm−1, 2860-2950 cm−1 and 1300-1380 cm−1 in infrared as a function of time of aging. Differences were also found in UV/VIS spectra, concerning bands of intensity of ca. 280 and 350 nm. 2D correlation analysis as well as the PCA method have allowed to distinguish between selected paper samples, through the specificity of the aging process that runs in them.Graphical abstractImage 1
       
  • Three transition metal complexes based on nicotinate: Synthesis, structure
           and adsorption properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Yu Xin, Na Zhang, Xiao Xin Han, Bing Li, Ying Sun, Li Xian Sun, Feng Ying Bai, Yong Heng XingThis work designed and synthesized three complexes by the hydrothermal synthetic method, They are [Zn (nic)2(H2O)2]n (1), [Ni2(nic)4 (μ2-H2O)]n (2), [Co2(nic)4 (μ2-H2O)]n (3), respectively. The complexes were characterized by elemental analysis, infrared spectrum, ultraviolet spectrum, thermogravimetric analysis and X-ray powder diffraction etc. The crystal structures of complexes 1–3 were measured by X-ray single crystal diffraction. Complex 1 formed a 3D supramolecular structure through hydrogen bonds, and complexes 2–3 formed 3D network structures with coordination bonds. The adsorption properties of complexes 1–3 on the coomass bright blue G250 (CBB) were tested, meanwhile, whose adsorption kinetics were also studied.Graphical abstractThree 3D metal-organic frameworks [Zn (nic)2(H2O)2] (1), [Ni2(nic)4 (μ2-H2O)] (2), [Co2(nic)4 (μ2-H2O)] (3) have been designed and synthesized by the hydrothermal synthetic method based on the ligand nicotinate. Complex 1 formed a 3D supramolecular structure through hydrogen bonds, and complexes 2–3 formed a 3D network structures with covalent bonds. Complexes 1–3 have better adsorption properties for dyes CBB, and the kinetics results show that the adsorption rates conform being the quasi-second-order kinetics model.Image 1
       
  • Thermal stability of the Cu–ZrTe2 intercalation compounds
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Alexey S. Shkvarin, Alexey A. Titov, Mikhail S. Postnikov, Jasper R. Plaisier, Lara Gigli, Mattia Gaboardi, Alexander N. Titov, Elena G. ShkvarinaAbstractAn experimental study of the phase stability of the CuxZrTe2 compound (0 
       
  • 1H NMR linewidths of small organic guest molecules physisorbed on
           different mesoporous silicas
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Gábor SzalontaiThe excessive linewidths of 1H NMR spectra of solids is a longstanding difficulty. Organic molecules (crystalline at room temperatures) of different chemical characters (camphor, menthol, HMB, HMTA, biphenyl, terphenyl, anthracene, perylene, etc.) have been confined or physisorbed in regular (MCM-41, SBA-15) and irregular (aerogel) silica mesopores. Unexpectedly, steadily decreasing proton NMR linewidths have been observed upon increasing pore sizes. Comparison of the static 1H NMR spectra of the confined and “free” bulk molecules showed an impressive resolution improvement (a factor of 5–10). Static 1H NMR and 2H magic angle spinning (MAS) spectra pointed out the increased molecular mobility as origin. In a qualitative approach the possible reasons of mobility have been thoroughly discussed. The increased mobility seems to be easiest achievable in aerogel and so, in the future, this extreme light mesoporous silica nanomaterial (MSN) may be considered as “active” filling material in solid state NMR spectroscopy. Since sensitivity is not an issue in 1H MAS measurements the proposal - simultaneous dilution of the dense 1H–1H spin network and increasing the molecular mobility of the molecules of interest by confinement or physisorption in/on silica mesopores - may find applications, especially in laboratories where high magnetic fields and state of art ultra-fast MAS rotation are not available.Graphical abstractImage 1
       
  • Excited-state photocycodimerization of 6-azauracil to oxazetidine
           cyclodimer: A mechanism elucidation in water surroundings
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Vassil B. Delchev, Ernst Horkel, Dennis SvatunekAbstractThe crystal structure of 6-azauracil was proposed by the X-ray powder diffraction pattern of the compound. The packing of the molecules in the unit cell (number of molecules Z = 4) was investigated. A stacked dimer model was chosen from the unit cell for the subsequent theoretical investigation of the mechanism of cyclodimerization to oxazetidine cyclodimer. The mechanism of the transformation of the stacked dimer to oxazetidine cyclodimer through a conical intersection S0/S1 was proposed. The phototransformation occurs along the 1ππ* excited-state reaction path. The calculations were performed at the BLYP theoretical level (Becke-Lee-Yang-Parr functional) and the basis set cc-pVDZ in water surroundings, according to the polarized continuum model (PCM).
       
  • Synthesis, DFT calculations and molecular docking study of mixed ligand
           metal complexes containing 4,4′-dimethyl-2,2′-bipyridyl as
           α-glucosidase inhibitors
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Davut Avcı, Sümeyye Altürk, Fatih Sönmez, Ömer Tamer, Adil Başoğlu, Yusuf Atalay, Belma Zengin KurtNovel mixed ligand metal complexes including 4,4′-dimethyl-2,2′-bipyridyl (dmdpy) and 6-methylpyridine-2-carboxylic acid (6-mpaH) {[VO(6-mpa)(dmdpy)]·SO3, (1), [Fe(6-mpa)(dmdpy)(NO3)2]·NO3, (2), Ni(6-mpa)(dmdpy)Cl2, (3), [Zn(6-mpa)(dmdpy)Cl2]·H2O, (4), Cd(6-mpa)2(dmdpy), (5), [Hg(6-mpa)(dmdpy)(NO3)2]·H2O, (6)} were synthesized as potential α-glucosidase inhibitors. Their structural characterizations, vibrational and electronic spectral behaviours were investigated by elemental analysis, LC-MS/MS, FT–IR and UV–Vis spectroscopic techniques. The inhibitory activities of these complexes against α-glucosidase (from Saccharomyces cerevisiae, EC No: 3.2.1.20) were determined. The synthesized complexes 1–6 exhibited α-glucosidase inhibitory activity with the IC50 values ranging from 0.4699 to>600 μM. Besides, density functional theory (DFT) calculations in the mode of hybrid HSEh1PBE method with 6-311G(d,p) and LanL2DZ basis sets for optimal complex geometries were fulfilled to obtain the vibrational frequencies and electronic spectral behaviours as well as substantial contributions to the electronic transitions. Furthermore, the molecular docking study was performed to examine protein-ligand interactions between the synthesized complexes (1–6) and target protein (the template structure S. cerevisiae isomaltase (PDBID: 3A4A)).Graphical abstractImage 1
       
  • Antioxidant properties of aqueous selenium nanoparticles (ASeNPs) and its
           catalysts activity for 1, 1-diphenyl-2-picrylhydrazyl (DPPH) reduction
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Nilesh S. Dumore, Mausumi MukhopadhyayIn this work, Aqueous selenium nanoparticles (ASeNPs) was prepared from sodium selenite (Na2SeO3) as a precursor by using gallic acid (GA) as a reducing agent in wet chemical methods. The morphology, particle size, structure, and free radical scavenging (FRS) activity of ASeNPs were characterized by high-resolution transmission electron microscopy (HRTEM), ultraviolet–visible spectroscopy (UV–vis), fourier transform infrared (FTIR), energy-dispersive X-ray spectroscopy (EDAX), dynamic light scattering (DLS), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Synthesized ASeNPs showed uniform sphere-shaped with an average particle size range of 98 nm. EDAX analysis confirmed the existence of selenium in the nanosphere. FTIR results show that hydroxy (-OH), carboxyl (-CO), alkyl (C–H) functional groups on the surface of ASeNPs. The percent scavenging of DPPH of ASeNPs for initial reaction pH 6, 6.5, 7 and buffer 7 was obtained as 80.6%, 84.0%, 83.0% and 73.0% respectively. The DPPH radical scavenging activity of ASeNPs without using any stabilizer and capping agent in this work reached higher than 80% in 1.0 ml of ASeNPs. The percent scavenging of ABTS of ASeNPs for initial reaction pH 6, 6.5, 7 and buffer 7 was obtained as 85.7%, 94.9%, 93.8%, and 75.1% respectively. Apparent rate constant (kapp) for FRS reactions of DPPH increases linearly with an increasing concentration of ASeNPs, an increase in the kapp value was because of the accessibility of more interaction sites of ASeNPs.Graphical abstractImage 1
       
  • A study on up-conversion and energy transfer kinetics of KGdF4:Yb3+/Er3+
           nanophosphors
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Aman Prasad, A.S. Rao, G. Vijaya PrakashPotassium gadolinium fluoride (KGdF4) up-conversion nano particles (UCNPs) doped with ytterbium (Yb3+) and co-doped with erbium (Er3+) ions were prepared via wet chemical route. Morphological confirmation was achieved through high resolution transmission electron microscopy (HR-TEM) and EDAX studies. The size of the nanoparticles lie in the range of 5–7 nm. The samples emit intense up-converted green light centered at 545 nm (4S3/2 → 4I15/2) under 980 nm CW laser excitation. A red emission centered at around 650 nm (4F9/2 → 4I15/2) is also seen. Detailed study on up-conversion process showed involvement of energy transfer (ET) and ground/excited State absorption (ESA/GSA) processes between dopant ions. Decay kinetics of these UCNPs at 545 nm emission under 980 nm CW laser excitation were studied. These UCNPs exhibit lifetimes in the range of 0.909 ms–1.162 ms. Inokuti- Hirayama (I–H) model was applied to establish the mechanism of energy transfer between the dopant ions. I–H model analysis proved that the interaction between Yb3+ and Er3+ ions is dipole-dipole in nature. Electron paramagnetic resonance (EPR) study was conducted to study the effect of having Gd3+ in the host lattice. The observed g values in the EPR spectra correspond to the characteristic “U” spectrum of gadolinium. Given their small sizes, ability to exhibit up-conversion and high lifetimes, we propose to utilize these UCNPs for bio-photonic applications.Graphical abstractFigure: Upconversion Spectra of KGdF4: Yb3+(x%)/Er3+(5%) [x = 5, 10, 15 and 20 mol%] under 980 nm CW laser excitation.Image 1
       
  • Ligand-based pharmacophore filtering, atom based 3D-QSAR, virtual
           screening and ADME studies for the discovery of potential ck2 inhibitors
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): A. Mohan, R. Kirubakaran, J.A. Parray, R. Sivakumar, E. Murugesh, M. GovarthananAbstractIn the era of druggable genome, the assessment of the numerous molecular targets represents remarkable therapeutic opportunities in the pharmaceutical and chemical biology, simultaneously understanding the properties required for the small molecules to emerge as good drug candidate. Incorporation of readily amenable biological properties and pharmaceutical modulation is the core key for the small molecule driven target studies in cancer related disease, especially in the case of inhibitory type mechanisms. Among huge protein targets, CK2 which is a protein serine/threonine kinase, also called the “Predominant monitor” of the cell plays comprehensive role in the various cellular machinery pertaining to cell growth and cell death. Due to its ubiquitous nature and its activity to block its activity by small molecules resulting in favorably targeting prostate cancer, CK2 was identified to be the distinct element of our study. In this study, we invested rapid computational techniques to uncover the new CK2 inhibitors with promising pharmaceutical traits and advantages when matched with existing drugs. Initially, pharmacophore modeling and atom-based 3Dimensional-Quantitative structure activity relationship of 45 known CK2 inhibitors resulted in over few hundred hypotheses. The most excellent five point pharmacophore model (AAHHR) with two hydrogen bond acceptor (A), two hydrophobic groups (H), and one aromatic ring (R) was built. 3D-QSAR studies of the finest model yielded correlation co-efficient, R2 (0.9728) and Q2 (0.7965) for training and test set compounds respectively. Our effort of externally validating the generated QSAR model was quite momentous and encouraging with rm2 = 0.682, rcv2 = 0.779, k = 1.027 and r02 = 0.817 values points out the profoundness in predicting preeminence of model. The robust model was further employed as 3D query for virtual screening against ZINC database. The lead molecules were selected based on the fitness score, and then the lead molecules subsequently taken to molecular docking studies using Glide. Finally we identified six potential lead molecules were further subjected into ADME properties prediction by engaging Qikprop module. The ADME properties of six lead molecules ZINC15955420, Zinc13412605, Zinc40763681, Zinc40763677, Zinc26178676 and Zinc01536721 are under satisfactory range with desired ADME properties. On the whole, we believe our design of the new CK2 inhibitor serves as the approachable end resultant hits the can be researched further for clinical trials evaluation in prostate cancer and emphasize on choosing CK2 as the target that holds true protential for the genesis and proliferation of anti-CK2 agents to address prostate cancer therapeutics.
       
  • Complex water dynamics in crystalline [Ca(H2O)2](ReO4)2, studied by the
           vibrational spectroscopy and proton magnetic resonance
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Joanna Hetmańczyk, Łukasz Hetmańczyk, Paweł Bilski, Asja KozakA 1H nuclear magnetic resonance study of [Ca(H2O)2](ReO4)2 has confirmed the existence of one phase transition at TCh=261.2 K (on heating) and TCc=231.2 K (on cooling), detected earlier by the DSC method. These transitions were reflected by changes in the temperature dependences of second moments of NMR line M2H. The study revealed anisotropic reorientations of whole [Ca(H2O)2]2+ cations, and the reorientations by 180° jumps of H2O ligands. It was found that the phase transition at TC is associated with the reorientation of H2O signed by oxygen O10 in crystal structure in high temperature phase. The oscillations of the cation as a whole unit around the axis crossing Ca and the middle of O9–O10 distance take place in both phases. From the temperature dependence of the full-width at half-maximum values (FWHM) of the bands connected with ρr (H2O) mode in IR spectra, we can conclude that the reorientational motions of H2O ligands contribute to the phase transition mechanism. The ligands perform fast (τR ≈ 10−11 to 10−13 s) stochastic reorientational motions in the high temperature phase. The estimated mean value of activation energy for the reorientation of the H2O ligands is ca. 11.1 kJ mol from Raman spectroscopy (RS) and 11.6 kJ mol from infrared spectroscopy, which is consistent with NMR results.The proton-weighted phonon density functions G(ν) obtained at 5 K show some separate peaks characteristic for ordered phase. Additionally, IR, RS and IINS spectra were calculated by the DFT method and an excellent agreement with the experimental data was obtained using CASTEP code.Graphical abstractImage 1
       
  • Erythrocyte membrane vesicles coated biomimetic and targeted doxorubicin
           nanocarrier: Development, characterization and in vitro studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Güliz Ak, Şenay Hamarat ŞanlıerOvarian cancer is the most common cause of death within gynecologic cancers and doxorubicin is an anthracycline agent, is widely used in many cancer types. Folate receptor enables of accumulation folate linked nanoparticles into tumor cells and magnetic targeting also provides localized addressing. The aim of this work is to develop a magnetic and biomolecularly targeted biomimetic doxorubicin nanocarrier system for ovarian cancer therapy. Firstly, highly dispersed starch and PEG diacid coated magnetic nanoparticles were synthesized with an easy and fabricable method and 91.45 ± 1.07 μg doxorubicin was adsorbed on per mg magnetic nanoparticles. The structure was verified with FTIR, TGA, VSM, TEM and zetasizer. Then, folate linked erythrocyte membrane vesicles were prepared from ghost cells and doxorubicin loaded magnetic nanoparticles were encapsulated into vesicles through extrusion due to enabling avoidance from immun clearance. The final nanocarrier system was nearly spherical in shape and had a hydrodynamic size of 157.4 ± 33.2 nm. Drug release profile was determined as in a controlled manner and IC50 value against SKOV3 for 72 h was calculated as 0.74 ± 0.32 μg/mL which was lower than that of free doxorubicin. In conclusion, it was suggested that biomimetic doxorubicin nanocarrier system have many advantages for targeted ovarian cancer therapy.Graphical abstractImage 1
       
  • Homoleptic tin(IV) compounds containing tridentate ONS dithiocarbazate
           Schiff bases: Synthesis, X-ray crystallography, DFT and cytotoxicity
           studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Enis Nadia Md Yusof, Muhammad A.M. Latif, Mohamed I.M. Tahir, Jennette A. Sakoff, Abhi Veerakumarasivam, Alister J. Page, Edward R.T. Tiekink, Thahira B.S.A. RavoofSix new tin(IV) compounds derived from tridentate dinegatively charged ONS dithiocarbazate Schiff bases derived from 2-hydroxy-3-methoxybenzaldehyde (H2L1, H2L2 and H2L3) and 2,3-dihydroxybenzaldehyde (H2L4, H2L5 and H2L6) (where H2Ln = di-acids of Schiff base) are reported. The compounds were characterised by elemental analysis, FT-IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy. The crystal structures of tin(IV) [S-4-methybenzyl-β-N-(2-hydroxy-3-methoxybenzylmethylene)dithiocarbazate] (2) and tin(IV) [S-benzyl-β-N-(2-hydroxy-3-methoxy benzylmethylene)dithiocarbazate] (3) were determined by X-ray single crystal diffraction analysis. X-ray crystallography showed the molecular geometries in homoleptic 2 and 3 to be quite similar in which the dinegative tridentate ligand coordinated the tin atoms via thiolate-S, phenoxide-O and imine-N atoms. The coordination geometries are based on an octahedron with like-atoms mutually trans. The experimental findings were validated by density functional theory (DFT) calculations at the B3LYP/LanL2DZ/6-311G(d,p) level of theory. All the tin(IV) compounds, except the insoluble compound 2 were screened for their in vitro cytotoxicity against a panel ten of cancer cell lines and one normal breast cell line (MCF-10 A) by MTT assay. Interestingly, the cytotoxicity of five tin(IV) compounds against HT29, MCF7 and MIA was higher than the reference drug, cisplatin.Graphical abstractImage 1
       
  • Synthesis, characterization, X-Ray crystal study and bioctivities of
           pyrazole derivatives: Identification of antitumor, antifungal and
           antibacterial pharmacophore sites
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Abderrahim Titi, Mouslim Messali, Bakhet A. Alqurashy, Rachid Touzani, Takuya Shiga, Hiroki Oshio, Mohammed Fettouhi, Mehdi Rajabi, Faisal A. Almalki, Taibi Ben HaddaThe reaction of hydroxymethyl pyrazole derivatives with one equivalent of the appropriate primary amine yields N-((1h-pyrazol-1-yl) methyl) pyrimidin-2-amine (L1), 2-(((1h-pyrazol-1-yl) methyl) amino) benzoic acid (L2), and ethyl 5-methyl-1-(((6-methyl-3-nitropyridin-2-yl) amino) methyl)-1h-pyrazole-3-carboxylate (L3). The structure of synthesized compounds (L1-L3) was identified by FT-IR, UV–visible, proton NMR spectroscopy, mass spectroscopy, and single crystal X-ray crystallography. The armed pyrazoles (L1-L3) were crystallized in the space groups C2/c, P21/n and P-1 for L1, L2, and L3 respectively. Crystallographic analysis revealed that N–H of the amine group and Nitrogen or Oxygen atoms are in-plane with the aromatic ring. The aminomethyl chain forms a distorted second plane. The angle between the two planes is observed to be 76.07° (N2–C7–N5–N19) for L1, 62.12° (N34–C63–N22–N35) for L2, 60.84° (N3–C8–N2–N1), and 0.41° (N1–C4–C3–O1/O2) for L3 was studied. Theoretical physical and chemical properties calculations have been performed on the studied armed pyrazoles (L1-L3) using three different programs: Petra, Osiris, & Molinspiration (POM). The geometric parameters of the optimized structure are in agreement with the experimental data obtained from the X-ray structures. The origin of the biological activity against breast cancer and microbes has also been confirmed.Graphical abstractImage 1020364
       
  • Structural, spectroscopic and thermal characterizations combined with DFT
           calculations and Hirshfeld analysis of a novel hydrogen-bonded complex:
           p-phenylenediammonium dinitrate
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): F. Berrah, F. Boursas, S. Bouacida, F. OuannassiThe compound p-phenylenediammonium dinitrate (PPDN) has been synthesized and its structure characterized by FT-IR, Raman and single crystal XRD techniques. Thermal behavior of this compound has been studied by TGA/DSC analysis. The three-dimensional framework observed in the PPDN structure is mainly maintained thanks to conventional N–HO hydrogen bonds and weak C–H…O contacts. In the p-phenylenediammonium cation, four carbon atoms of the aromatic ring are disordered over two positions with half occupancy. The geometry, modes of vibrations, atomic charges, thermodynamic parameters and frontier molecular orbitals of the PPDN molecule have been calculated by DFT method at B3LYP/6–311++G(d,p) and B3LYP/cc–pVTZ levels. The intermolecular bonding interactions within this molecule have been investigated using the natural bonding orbital (NBO) analysis at B3LYP/cc–pVTZ level. The 3-D Hirshfeld surface and the associated 2-D fingerprint plot, calculated for the PPDN molecule, have showed the clearly dominance of the H…O/O…H and H…H contacts which together represent more than 80% of the total surface.Graphical abstractImage 1
       
  • Anisotropic rotation dynamics of the CH3 radical impurity in solid Ar by
           tracking the low temperature motionally averaged static EPR parameters
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Yurij Dmitriev, Nikolas BenetisAbstractThe present detailed motional dynamics study of the CH3 radical in solid Ar paves the way for the methodology development of the EPR lineshape simulation of the radical as a paramagnetic probe to determine ordering and dynamics in solid matrices. Even systems with important practical applications as e.g. solid methane CH4 matrices are included. Characteristic temperature dependence details of the EPR spectrum anisotropy and broadening contain significant information about the radical matrix interaction and the matrix structural relaxation. In the fcc Ar crystal lattice the substitutionally trapped CH3 performs anisotropic rotation with three different principal values of the rotation tensor testifying lattice relaxation leading to reduced symmetry surrounding of the methyl probe compared to the initial octahedral. The investigation reveals also the striking difference in the impurity-host interaction between the A-symmetry and E-symmetry methyls.
       
  • Crystal structures of organic salts of chloranilic acid and
           2,2′-bi(3-hydroxy-1,4-naphthoquinone) acting as proton donors to
           4,4′-Bipyridine and 1,4-Diazabicyclo[2.2.2]octane: 3D networks with
           bifurcated N+-H···O−/O or N+-H···O/Cl synthons
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Martha V. Sosa-Rivadeneyra, María G. Vasquez-Ríos, Eva C. Vargas-Olvera, M.E. Mendoza, Jenaro L. Varela-Caselis, Rosa Luisa Meza-León, María Obdulia Sánchez-Guadarrama, Herbert HöpflFive organic salts were prepared by proton transfer from organic acids to nitrogenous bases using chloranilic acid (H2CLA) or the Lawsone dimer (H2LD) as proton donors and 1,4-diazabicyclo[2.2.2]octane (DABCO) or 4,4′-bipyridine (BPY) as proton acceptors, viz., [(H2BPY)(CLA)]⋅4H2O, [(HDABCO)2(CLA)]⋅2H2O, [(HDABCO)2(CLA)]⋅6H2O, [(H2DABCO)(HCLA)2]⋅2H2O, and [(H2DABCO)(LD)]⋅H2O. The molecular crystal salts were characterized by elemental analysis, single-crystal X-ray diffraction (SCXRD) analysis, infrared spectroscopy and TG-DSC measurements. The SCXRD studies revealed that the molecular crystals studied herein are all hydrates with extensive and diverse hydrogen bonds of the N+−H⋅⋅⋅O−/O, N+−H⋅⋅⋅O/Cl, Ow−H⋅⋅⋅O−/O, Ow−H⋅⋅⋅Cl, Ow−H⋅⋅⋅N, Ow−H⋅⋅⋅Ow, and C–H⋅⋅⋅N type, which in some cases were accomplished by π–π, Cl⋅⋅⋅Cl or Cl⋅⋅⋅O contacts. Common to all crystal structures is the presence of cation-anion aggregates formed through bifurcated N+−H⋅⋅⋅O−/O or N+−H⋅⋅⋅O/Cl hydrogen bonds. All compounds constitute infinite 3D supramolecular networks based essentially on hydrogen bonding or a combination of hydrogen bonding and π-π interactions.In addition, ecofriendly preparative methods were tested for the preparation of the organic molecular crystal salts studied herein, viz., neat grinding, liquid-assisted grinding, slurry and precipitation.Graphical abstractImage 1
       
  • Synthesis of a novel phenytoin derivative: Crystal structure, Hirshfeld
           surface analysis and DFT calculations
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Walid Guerrab, Hassane Lgaz, Sevgi Kansiz, Joel T. Mague, Necmi Dege, M. Ansar, Riadh Marzouki, Jamal Taoufik, Ismat H. Ali, Ill-Min Chung, Youssef RamliHydantoin compounds are important heterocyclic scaffolds and a class of well-known bioactive molecules with a broad spectrum of pharmacological properties. Consequently, considerable efforts have been devoted to the design and synthesis of a broad range of hydantoin derivatives. In this context, the compound 3-allyl-5,5-diphenylimidazolidine-2,4-dione, C18H16N2O2 (3ADID) was synthesized and its structure was determined by X-ray structure analysis. Further, the molecular structure was examined using Hirshfeld topology analysis and Density Functional Theory (DFT)-B3LYP calculations with the basis set 6–311++G (d,p). In the title molecule, C18H16N2O2, the imidazolidine ring is planar with the allyl substituent oriented nearly perpendicular to it. In the crystal, hydrogen bonded chains of molecules are arranged in sets of three about the 32 axes by C–H···π (ring) interactions. Hirshfeld surface map and 2D fingerprint plots were used to explore intermolecular interactions. The optimized geometry, global reactivity descriptors, and HOMO-LUMO orbitals of the molecule were computed by DFT and discussed. To evaluate the chemical reactivity and charge distribution on the molecule, molecular electrostatic potential (MEP) and atomic charges, computed by Mulliken population analysis and NBO theory were determined. The local reactivity was examined by determining the Fukui functions and dual descriptor indices. DFT calculations at the same level of theory, with the POPNBO keyword, were used to evaluate charge delocalization and hyperconjugative interactions through Natural Bond orbital analysis.Graphical abstractImage 1
       
  • Electronic structure and optical properties of Sm(III) and Eu(III)
           complexes with hexamethylphosphoramide
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): A.V. Shurygin, V.I. Vovna, V.V. Korochentsev, A.G. Mirochnik, P.A. Zhikhareva, V.I. SergienkoAbstractNitrate complexes Ln(NO3)3 of Sm(III) and Eu(III) lanthanides with three neutral ligands HMPA (OP(NMe2)3) possessing triboluminescent properties were studied by X-ray photoelectron spectroscopy (XPS MgKα) and quantum chemistry (DFT/TDDFT). Interpretation of the bands of XPS spectra of the valence levels and core levels was carried out using the calculated energies and localization of the Kohn-Sham orbitals. Using the DFT/TDDFT methods the influence of HMPA molecules on the electronic structure of lanthanide ion nitrate complexes was studied and the electronic effects of adduct formation are described. The nature of the bond of nitrate complexes with neutral molecules was revealed. The binding energy of Ln(NO3)3 (Ln = Sm, Eu) with three HMPA molecules was determined theoretically (Sm(NO3)3(HMPA)3–5.17 eV, Eu(NO3)3(HMPA)3–4.11 eV). The relationship of the electronic structure with the absorption and excitation spectra, optical characteristics and its role in reducing the probability of the energy transfer from ligands to metal within the LMCT (ligand-to-metal charge-transfer) model is shown. The experimental and theoretical absorption spectra were obtained for the studied adducts possessing promising solubility properties in water. Prospects of further research of the intermolecular layers are shown for the crystals under study.
       
  • Intermolecular investigation on interaction of two ternary copper(II)
           Schiff base complexes with bovine serum albumin
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Hamid Dezhampanah, Roghaye Firouzi, Zeinab Moradi Shoeili, Reihaneh BinazirAbstractThis study was conducted to investigate the mechanism of the interaction between bovine serum albumin (BSA) and two ternary copper (II) Schiff base complexes by means of various spectroscopic techniques and molecular docking calculations. The results showed that both Schiff bases could effectively quench the endogenous fluorescence of BSA, forming 1:1 complexes and static quenching procedure due to the formation of the Schiff base-BSA complexes. Fӧrster energy transfer measurements, synchronous fluorescence spectroscopy, and docking studies showed that both Schiff bases bind to the tryptophan residues of BSA in short distances. Molecular docking results showed that both Schiff bases were bound in the hydrophobic cavity of BSA and were surrounded by active amino acid residues via forming several hydrogen and van der Waals bonds. Furthermore, as shown by the synchronous fluorescence and Fourier transform infrared spectroscopy, both Schiff bases could lead to the conformational changes of BSA, which might affect its physiological function.
       
  • Theoretical and experimental characterization of Cu-doped amorphous
           silicate glass
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Arshak A. Tsaturyan, Svetlana O. Cherkasova, Andriy P. BudnykThe coordinative environment of Cu2+ ions incorporated in oxide glasses has been intensively studied for glasses doped with copper ions by melting or ion exchange. Much less is known about their coordination in a sol-gel derived silicate glass. Mesoporous silicate glasses doped with copper (II) ions coming from four different salts were synthesized by the acid-catalyzed sol-gel method. The electronic and structural states of copper sites were probed by optical and X-ray spectroscopies. The experimental observations were confronted with the results of quantum-chemical calculations. The theoretical models consisted of four- and five-coordinated Cu2+-complexes, where water ligands were sequently replaced with the SiO44‒ tetrahedra. The best agreement between the experimental and theoretical electronic spectra has been reached for the four-coordinated Cu2+-complex with a water molecule and three or four SiO44‒ tetrahedra. The energy band gap intervals of 4.21–4.61 eV and 4.09–4.23 eV were estimated graphically by the TAUC plot method and from quantum-chemical modelling, respectively.Graphical abstractImage 1
       
  • A new chromenylium-cyanine chemosensor for switch-ON near-infrared copper
           (II) sensing
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Kaan KaraogluA highly selective and sensitive near-IR chemosensor having a chromenylium-cyanine backbone for the detection of Cu2+ in aqueous samples has been designed and synthesized. The sensor has exhibited linear optical response to copper ions at the range of 0–4.9 × 10−6 M in the presence of other competing metal ions, such as Na+, K+, Mg2+, Ca2+, Cr3+, Mn2+, Fe3+, Co2+, Ni2+, Zn2+, Al3+, Cd2+, Ag+, Sr2+, Pb2+, Hg2+ and Ba2+. The limit of detection (LOD) was calculated as 1.28 × 10−8 M which was lower than that of previously reported analogues. The sensor allows detection of the copper(II) ion through the spirocyclic ring-opening reaction by coordination of Cu2+.Graphical abstractImage 1
       
  • ii)+and+zinc+complexes&rft.title=Journal+of+Molecular+Structure&rft.issn=0022-2860&rft.date=&rft.volume=">Morpholine-N-carboxylate as a ligand in coordination chemistry –
           Syntheses and structures of three heteroleptic copper(ii) and zinc
           complexes
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Nikola Bedeković, Vladimir StilinovićThe first three morpholine-N-carboxylate complexes, with copper(II) and zinc(II) have been prepared and studied by single crystal X-ray diffraction. All three compounds comprise of discrete mono- or dinuclear heteroleptic complex molecules. Three different ways of bonding of morphCOO– anions have been observed – as a monodentate, chelating, and as a bridging ligand. In all cases only the carboxyl group of the morpholinecarboxylate anion was found to bind to the metal cation, while the oxygen atom of the morpholine ring participates only in weak C–H‧‧‧O hydrogen bonds. Changes in the geometry of the coordinated morphCOO– anion relative to the free ligand (in its morpholinium salt) were observed in all three modes of binding to the metal center.Graphical abstractImage 1
       
  • Pd(II) and Ni(II) complexes containing an asymmetric Schiff base ligand:
           Synthesis, x-ray crystal structure, spectroscopic investigations and
           computational studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Hadi Kargar, Vajiheh Torabi, Alireza Akbari, Reza Behjatmanesh-Ardakani, Atefeh Sahraei, Muhammad Nawaz TahirA new N2O2 Schiff base ligand bis(5-Bromosalicylidene)-4-methylbenzene-1,2-diamine), [H2L] was prepared from the reaction of 4-methylbenzene-1,2-diamine with 5- bromosalicylaldehyde. From the direct reaction of ligand [H2L] with nickel(II) and palladium(II) salts in methanol and acetonitrile solutions the neutral [NiL] and [PdL] complexes were prepared. The products were characterized using elemental analyses, FT-IR, UV–Vis, 1H NMR spectroscopy techniques. The results indicate that all compounds are successfully synthesized. The crystal structure of the Pd(II) complex was also determined. X-ray crystal structure of [PdL] showed that the complex contains palladium(II) in a distorted square planar environment of N2O2 donors. DFT and TD-DFT calculations have been done using M06–2X and B3LYP levels with Def2-TZVP and ATZP basis sets. The quantum chemical calculations supported the experimental crystal structure of [PdL] complex. The proposed coordination geometry around the Ni atom in [NiL] complex is defined as slightly distorted square planar by DFT studies. NBO-CMO calculations have been performed to interpret electronic transitions.Graphical abstractNew Schiff base ligand (H2L) and its complexes were prepared and characterized; the XRD structure of the Pd complex was also determined. Quantum chemical calculations supported the distorted square planar experimental coordination geometry of the [PdL] complex. NBO-CMO calculations have been performed to interpret electronic transitions.Image 1
       
  • Unravelling the distinctive mode of cooperative and independent
           interaction mechanism of 1-butyl-2,3-dimethylimidazolium tetrafluoroborate
           ionic liquid with model transport proteins by comprehensive spectroscopic
           and computational studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Arumugam Selva Sharma, Annavaram Viswadevarayalu, A. Christian Bharathi, Krishnan Anand, Shujat Ali, Huanhuan Li, B. Syed Ibrahim, Quansheng ChenAbstractIn the present investigation, a detailed spectroscopic analysis on the interaction mechanism of 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate [Bdmim][BF4] with human serum albumin (HSA) and bovine serum albumin (BSA) has been carried out by multispectroscopic studies. The results obtained from the fluorescence titration experiments indicated the existence of a weak interaction between HSA/BSA and [Bdmim][BF4]. The binding parameters revealed that [Bdmim][BF4] binds to HSA by cooperative process, while in the case of BSA the binding of [Bdmim][BF4] is found to be independent to the binding sites having the similar affinity. The outcome of the CD and absorbance spectral experiments of HSA/BSA-[Bdmim][BF4] systems revealed the occurrence of very little modifications in the micro-environmental and secondary structural conformations of HSA/BSA. Autodocking and molecular dynamics simulation studies indicated that the positively charged imidazolium moieties of ionic liquid (IL) is located in the vicinity of subdomain IIA and subdomain IB in HSA and BSA, respectively. The enzyme-like activity of HSA/BSA is inhibited slightly upon complexation with [Bdmim][BF4].
       
  • Aceclofenac and interactions analysis in the crystal and COX protein
           active site
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Christian Jelsch, Rajendran Niranjana Devi, Bruce C. Noll, Benoît Guillot, Israel Samuel, Emmanuel AubertAn experimental charge density analysis of the anti-inflammatory drug aceclofenac has been accomplished and compared with periodic Density Functional results. Diffraction data sets were measured on two crystals on a Bruker Photon II detector. The merging of the two data sets resulted in improved crystallographic R-factors. The analysis of the intermolecular contact types and their enrichments highlights the driving forces of the crystal packing. Strong hydrogen bonds C=O…H–O between carboxylic groups act as one of the main backbones in the crystal packing while halogen bonding Cl…O and the non-polar contacts C–H…Cl are also well represented. The C6H4Cl2N heterocycle forms aromatic donor–acceptor parallel self-interactions through an inversion center while the less substituted C6CH4N cycle is more involved in C–H…π interactions. The N atom linking the two phenyl rings presents mixed sp2/sp3 hybridization and bears a weak but visible electron lone pair.The electrostatic potentials generated by the molecule and by its surrounding on the Hirshfeld surface were analyzed and show a good electrostatic complementarity for the charged regions of the molecule, while the non-polar regions interact with each other. The electrostatic energies computed between interacting dimers in the crystal show that the strongest dimer is the one forming two O–H...O hydrogen bonds. The electron density ellipticity and Laplacian values were analyzed on the covalent bonds critical points. The C–H bonds on the two aromatic C6 rings have a modest but significant ellipticity value  = 0.048, presumably due to the proximity of the C–C bonds with π character of the carbon atoms involved in the bonds. Theoretical geometry optimizations performed on the isolated molecule and on crystallographic dimers show the effect of the intermolecular interactions on the molecular conformation, which is slightly affected by the crystal packing.The aceclofenac medicinal compound, metabolized into diclofenac after loss of an acetic acid group, binds in vivo to the target COX-2 protein. An electron density model of diclofenac has been derived from the refined electron density of aceclofenac. The interactions between diclofenac and the protein were analyzed from an electrostatic and a Hirshfeld surface analysis points of views.Graphical abstractImage 1
       
  • Novel d- and f-metal phthalocyaninates based on
           4-(2,4,5-trichlorophenoxy)phthalonitrile. Synthesis, spectroscopic and
           fluorescent properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Anna Botnar, Tatyana Tikhomirova, Kseniya Nalimova, Dmitry Erzunov, Mikhail Razumov, Artur VashurinThe work reports synthesis and spectroscopic-luminescent properties of first obtained zinc, magnesium, erbium and gadolinium trichlorophenoxy-phthalocyanine complexes. The initial building unit being 4-(2,4,5-trichlorophenoxy)phthalonitrile is synthesized by nucleophilic substitution reaction. Zinc and magnesium complexes are obtained by template condensation of the phthalodinitrile and corresponding acetates. A demetallization of magnesium phthalocyaninate results in the formation of free tetra-4-(2,4,5-trichlorophenoxy)phthalocyanine ligand. Rare-earth element complexes are synthesized by two approaches: template condensation and metallization of free phthalocyanine ligand. The planar complex is found to be yielded higher in case of template fusion. Influence of lanthanide salts anion (acetate, chloride) on formation ability of sandwich-type complex is analyzed. A double-decker complex is testified to be formed only upon the template fusion of gadolinium acetate with 4-(2,4,5-trichlorophenoxy)phthalonitrile. The as-obtained compounds are studied in terms of spectral-luminescent characteristics. A bathochromic shift of absorption Q-band maximum is found to accompany d-to-f-metal transition. The zinc complex being associated in chloroform exhibits higher quantum yield of fluorescence than monomeric forms generated upon addition of organic ligand.Graphical abstractImage 1
       
  • Investigation on structural, optical, dielectric, mechanical and thermal
           properties of 4-methoxyaniline hydroquinone cocrystal: A promising optical
           power limiting material
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): V. Siva, A. Shameem, A. Murugan, S. Athimoolam, M. Suresh, S. Asath BahadurA new non proton transfer compound, Bis(4-methoxyanline) hydroquinone (4MAHQ) has been produced and crystal obtained by the room temperature solvent evaporation technique. The corresponding crystal structure and influence of intra-molecular hydrogen bonding interactions have been reported. SCXRD study exposes that 4MAHQ crystallizes in triclinic system. The crystals were subjected to thermal, mechanical, dielectric and optical and NLO studies. The thermal stability was studied by TG/DTA and the crystal is found to have been stable up to 185 °C. The mechanical properties were obtained from Vickers’s hardness studies. The dielectric responses of the crystal were studied for different frequencies versus variable temperature between 303 and 373 K. The transparency of the crystal in the range 330–1100 nm was confirmed by Ultraviolet–visible spectral studies. The Z-scan study confirmed the existence of high third order nonlinear optical susceptibility in 4MAHQ.Graphical abstractHydrogen bonding motif chain C21(4) motif extending along b-axis of the unit cell are shown. H-bonds are shown as dashed lines.Image 106829
       
  • New Pd-PEPPSI complexes bearing meta-cyanobenzyl-Substituted NHC:
           Synthesis, characterization, crystal structure and catalytic activity in
           direct C–H arylation of (Hetero)arenes with aryl bromides
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Ferhat Türker, İmran Bereket, Duygu Barut Celepci, Aydın Aktaş, Yetkin GökAbstractThe prestige of the PEPPSI (Pyridine-Enhanced Precatalyst Preparation Stabilization and Initiation) complexes in organometallic chemistry is increasing day by day. Herein, the well-defined seven meta-cyanobenzyl-substituted N-heterocyclic carbene (NHC)–Pd(II)-pyridine (Pd-PEPPSI) complexes were synthesized using palladium acetate, which unlike general procedure is a more economical method than palladium chloride. The new Pd-PEPPSI complexes were obtained from the reaction of the cyanobenzyl substituted NHC precursors and palladium acetate in pyridine. The new complexes have been fully characterized by 1H NMR, 13C NMR, FTIR spectroscopy and elemental analysis techniques. Also, the X-ray diffraction method was used to determine the single-crystal structure of a complex. The Pd-PEPPSI complexes have been examined as catalysts in the direct arylation reactions of 2-n-butylfuran and 2-n-butylthiophene with aryl bromide. All complexes have demonstrated excellent activity in these reactions. The Molecular and crystal structure of one of the cyanobenzyl substituted Pd-PEPPSI complexes was determined by the single-crystal X-ray diffraction method. X-ray diffraction studies show that the molecular structure adopts a slightly distorted square-planar geometry with the palladium (II) center.
       
  • Structural, magnetic and Mössbauer analysis of lanthanum and nickel doped
           Co2Y-type hexaferrite nanomaterial matrix synthesized by sol-gel
           auto-combustion technique
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Monika Chandel, Virender Pratap Singh, Kirti Singha, Susheel Kalia, Rajesh Kumar, Gagan Kumar, M. SinghSol-gel auto-combustion technique was used to prepare the lanthanum (La3+) and nickel (Ni2+) doped Co2Y-type Sr2-yLayCo2NixFe12-xO22; x = 0.0, 0.1, 0.2, 0.3; y = 0.0, 0.01, 0.02, 0.03 nanohexaferrites materials. Synthesized nanohexaferrites were characterized by XRD, FTIR and EDS analysis. The collective XRD analysis reveals the single-phase patterns corresponding to various dopants concentration in the powder system matrix. The calculated structural - auxiliary parameters viz. Lattice constants (a and c), cell volume (Vcell), X-ray density (dx), bulk density (db) and porosity (P) have been found in range; a = 5.8798–5.8321 Å, c = 43.7316–44.7214 Å, Vcell = 1309.303–1317.304 Å3, dx = 5.014–4.987 gm/cm3, db = 3.774–3.128 gm/cm3 and P = 0.247–0.37. The XRD results were supported by FESEM and TEM images, which showed the plate-like shape of particles. Unlike irregular grains, regular platelet-like grains were composed of several crystallites with almost parallel c-axis and this is the most suitable shape for microwave absorption. Fourier-transform infrared spectroscopy (FTIR) showed the location of the ions including their respective bonds within the structure of the lattice matrix and variation of ion concentration was depicted by EDS analysis of the powder matrix. The investigation of magnetic properties was done by vibrating sample magnetometer (VSM). The saturation magnetization (Ms) and coercivity (Hc) were found to be in the range of 34.29–43.711 emu/g and 16.27–299.441 Oe, respectively. The improved values of Ms and Hc mean that these powders can be used as pre-eminent contestant materials for perpendicular recording media (PMR) applications. In addition, the synthesized Co2Y-type nanohexaferrites were characterized for the Mössbauer analysis at room temperature. The normal Zeeman (six-line patterns) splitting confirms the hexagonal phase of synthesized nanohexaferrites.Graphical abstractImage 1
       
  • Synthesis and photoluminescence of color tunable red emitting Ba2YAlO5:
           Eu3+ phosphors
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Huan Duan, Ruirui Cui, Xiaosi Qi, Chaoyong DengAbstractSingle-composition Ba2YAlO5: Eu3+ (BYAO: Eu) red luminescent phosphor were prepared through high temperature solid-state reaction. The crystal structure and luminescence properties were studied via X-ray diffraction and photoluminescence spectra. Upon 468 nm excitation, the main emission peaks of BYAO: Eu phosphors locate in the 582, 591, 614 and 705 nm, corresponds to the 5D0→7FJ (J = 0–3) conversion of Eu3+ ions. In Eu3+ singly doped BYAO phosphor, the optimum doping concentration and transfer distance was 20 mol%, 11.16 Å, respectively. Under 468 nm excitations, the phosphors of BYAO: Eu showed obvious thermal quenching properties and the 473 K luminescence intensity was 74.4% of 298 K. Moreover, the CIE chromaticity coordinate range from yellow-green to red through changing the concentration of Eu3+ ions, and calculated value of purity is 96.4%. it indicates that BYAO: Eu phosphor is potentially promising material for commercial red phosphors.
       
  • V-shaped dicarboxylate ligands induced structural variation of Zn(II)
           complexes based on N-heterocyclic ligand from 1D to 3D: Synthesis,
           structures and luminescence properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Yungen Ran, Nan Hao, Xinlong Wu, Jinyu Li, Yajuan MuIn this work, three V-shaped dicarboxylate ligands, 5-tert-butyl isophthalic acid (H2tbip), 5-hydroxyisophthalic acid (H2hip) and 4,4′-carbonyldibenzoic acid (H2cba) were employed as coligands to make a comparison on the structures of Zn(II)-mbbt coordination polymers (mbbt = 1-(2-methylbenzimidazol-1-ylmethyl)benzotriazole). Three new complexes, [Zn2(mbbt)(tbip)2]n (1), {[Zn(mbbt)(hip)(H2O)]·2H2O·mbbt}n (2) and [Zn(mbbt)(cba)]n (3) have been synthesized and characterized. Structural analyses indicate that complex 1 displays a 3D 66 topology based on triangular Zn2(COO)3 SBUs; complex 2 shows an infinite 1D chain; complex 3 presents a 2D 44-sql network based on paddle-wheel-like Zn2(COO)4 SBUs. The structural differences of the three complexes suggest that the V-shaped dicarboxylate ligands can tune the structural dimensionality of Zn(II)-mbbt complexes. Furthermore, the photoluminescence properties of 1–3 were studied in the solid state at room temperature.Graphical abstractThree Zn(II)-mbbt coordination polymers have been synthesized by varying the V-shaped dicarboxylate ligands. Complex 1 shows a 66 topology based on triangular Zn2(COO)3 SBUs; complex 2 exhibits an infinite 1D chain; complex 3 presents a 2D 44-sql network based on Zn2(COO)4 SBUs. The structural differences suggest that the V-shaped dicarboxylate ligands can tune the structural dimensionality of Zn(II)-mbbt complexes.Image 1
       
  • In binary solvent: Synthesis and physicochemical studies on the
           nano-metric palladium(II) oxide associated from complexity of
           palladium(II) ions with gatifloxacin drug as a bio-precursors
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Khaled AlthubeitiAbstractThis article aimed to synthesized of palladium(II) oxide in nanoscale range using three palladium(II) gatifloxacin(GFX) complexes as a bio-precursors. These complexes were characterized using microanalytical, spectroscopic (infrared, electronic, 1H,13C NMR, and X−ray powder diffraction (XRD)), morphological (scanning electron microscopy (SEM) and Energy−dispersive X−ray (EDX)), and thermal analyses. The elemental analysis suggested that the stoichiometry of the synthesized palladium complexes are 1:2 (Pd2+:GFX) as [Pd(GFX)2]Cl2 and 1:1:1 (Pd2+:GFX:AA) complexes as [Pd(GFX)(AA)]Cl2 (where AA is glycine (Gly) or alanine (Ala) amino acids). The bi−dentate GFX drug ligand coordinated towards Pd2+ metal ion through nitrogen atoms of piperazine ring. The GFX complexes have an electrolytic behavior according to molar conductance test. The thermal stability of the Pd(II) precursors were discussed depend on thermal analyses TGA/DTA and kinetic thermodynamic calculations (activations of energy, entropy, enthalpy and Gibbs free energy) using non−isothermal methods. Nano-metric palladium(II) oxide was prepared by the thermal decomposition route using the three synthesized bio-precursors of GFX complexes after calcinations in an oxygenated medium at 600 °C for 3 h. The chemical composition, morphological and particle size of synthesized PdO was discusses based on FT-IR, XRD, SEM and EDX analyses. The catalytic efficiency of the PdO oxide in case of decomposition reaction of H2O2 was discussed.
       
  • 2-Halo- and/or 4-ethoxycarbonyl-substituted asymmetric 1,3-diaryltriazenes
           and 1,3-diarylamidines as well as N-methylated congeners
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Silvio Preusser, Paul R.W. Schönherr, Helmar Görls, Sven Krieck, Wolfgang Imhof, Matthias Westerhausen1,3-Diaryltriazenes Ar–NN–N(R)-R’ [R = H; Ar/R’ = C6H4-4-COOEt/Ph (1), C6H3-2-Br-4-COOEt/Ph (2), CH2Ph/C6H4-4-COOEt (3)] and the N-methylated congeners [R = Me; Ar/R’ = C6H4-4-COOEt/Ph (9), C6H2-2,5-Br2-4-NH2/Ph (10), C6H4-4-Br/C6H4-4-COOEt (11), C6H2-2-Br-4-COOEt/Ph (12), C6H2-2-Br-4-COOEt-6-Me/C6H4-2-Me (13), C6H3-2-Br-4-F/Ph (14), C6H3-2-Br-6-F/Ph (15), C6H3-2-Br-4-Cl/Ph (16), C6H3-2,4-Br2/Ph (17)] as well as 1,3-diarylformamidines of the type Ar–NCH–N(R)-R’ [R = H; Ar/R’ = C6H3-4-COOEt/Ph (4), C6H3-2-Br-4-COOEt/Ph (5), C6H3-2-Br-4-F/Ph (6)] and 1,3-diaryl-3-methylamidines [R = Me; Ar/R’ = C6H3-4-COOEt/Ph (18), C6H3-2-Br-4-COOEt/Ph (19), C6H3-2-Br-4-Cl/Ph (20), C6H3-2,4-Br2/Ph (21)] crystallize preferably with (syn-E) configuration. For comparison reasons sterically crowded Ph-N(R)-C (R′) = N–C6H3-2-Br-4-COOEt [R = H, R’ = Ph (7), tBu (8); R = Me, R’ = Ph (22), tBu (23)] are included. Large substituents destabilize this isomeric form due to intramolecular steric repulsion. 1,3-Diarylformamidines dimerize via two nearly parallel N–H⋯N hydrogen bridges. This kind of aggregation is very beneficial because the NC–N bond angles are slightly larger than 120°. Narrower NN–N bond angles are found for the 1,3-diaryltriazenes and therefore, aggregation occurs via intermolecular N–H⋯O hydrogen bridges to O-Lewis bases. The 1,3-diaryl-3-methylformamidines and -triazenes show very similar bonding parameters. Thus, the bond lengths of the NC/NN double bonds are approx. 4–9 pm shorter than the N–C/N–N single bonds, supporting charge delocalization within the diazaallyl- and triazaallyl systems regardless of N-methylation.Graphical abstractImage 1
       
  • Vibrational spectroscopic studies (FTIR and FT-Raman) and molecular
           dynamics analysis of industry inspired 3-amino-4-hydroxybenzene sulfonic
           acid
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): D. Ramarajan, K. Tamilarasan, Žiko Milanović, Dejan Milenković, Zoran Marković, S. Sudha, E. KavithaIn the present study, structural properties of 3-amino-4-hydroxybenzene sulfonic acid (3A4HBSA) have been studied extensively utilizing Density Functional Theory (DFT) by employing three common functionals (B3LYP-D3BJ, M06–2X and APF-D). The FTIR and FT-Raman spectra of 3A4HBSA were recorded. The Vibrational frequencies of 3A4HBSA in the ground state have been calculated by using B3LYP-D3BJ method with 6–311 + g (2df,2p) basis set. The difference between the observed and scaled wavenumbers of most of the fundamentals is very small. The detailed interpretation of the infrared and Raman spectra of 3A4HBSA is also reported. The theoretical spectrograms for FTIR and FT-Raman spectra of the title molecule have also been constructed and compared with experimental spectra. Stability of the molecule arising from hyper conjugative interactions and charge delocalization has been analyzed by using Natural Bond Orbital (NBO) analyses. The calculated HOMO and LUMO energies show that charge transfer occurs within the molecule. Molecular docking and dynamic analyses are carried out in order to investigate the inhibitory nature of 3A4HBSA. The importance of the functional groups is proven in the molecular docking study through the interactions with human TDP1 protein.Graphical abstractImage 1
       
  • Two new Zn2+/Cd2+ Metal-Organic Frameworks (MOFs) constructed from
           asymmetrical tricarboxylic acid ligands
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Yan-Ning Wang, Shao-Dan Wang, He Qi, Wen-Jing Wang, Xuan-Xuan HaoTwo new Metal-Organic Frameworks (MOFs), namely, [Cd(HL1)(H2O)] 1, [H2(bpp)][Zn2(L2)2(bpe)]·2H2O 2 (H3L1 = 4-(5-carboxy-pyridine-3-yloxy)-phthalic acid, H3L2 = 3-(4-carboxy-phenoxy)-phthalic acid, bpe = 1,2-bis(4-pyridyl) ethylene, bpp = 1,3-bis(4-piperidyl) propane) have been isolated employing two V-shaped asymmetric tricarboxylic acid ligands under hydrothermal conditions. X-ray single-crystal diffraction analysis reveals that μ4-mode HL12− molecules propagate the Cd2+ centers into a 3-D network with point symbol of 66 for 1. One-dimensional channels are observed in 1, but because of 2-fold interpenetration phenomenon, these channels become small or disappear. 2 possesses a 2-D layered structure with (3, 4)-connected (42ˑ63ˑ8) (42ˑ6) topology. The carboxyl moieties for L2 molecules first extend the Zn2+ centers into a 1-D double chain, then via the interactions between Zn2+ and pyridine N atoms, the resulting 1-D double chain are strutted by the rigid bpe ligands to form a 2-D layer framework. It is noteworthy that one-dimensional channels of ca. 13 × 13 Å2 are observed. H2(bpp)2+ and two lattice water molecules occupy the space of the channels. The introduced bpp molecules only serve as the templating agent and are not involved in the formation of this layer network. The photoluminescence properties of 1 and 2 were investigated.Graphical abstractTwo novel MOFs have been isolated employing two asymmetric tricarboxylic acid ligands and their photoluminescence properties were investigated.Image 1
       
  • Structures of selected transition metal complexes with
           9-(2-hydroxyethyl)adenine: Potentiometric complexation and DFT studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Hassan H. Hammud, K. Travis Holman, Mousa Al-Noaimi, Nadeem Sadiq Sheikh, Amer M. Ghannoum, Kamal H. Bouhadir, Mamdouh S. Masoud, Ranjith Kumar KarnatiThe dissociation constants of ligand 9-(2-hydroxyethyl)adenine (9-HOEtAde) and the molecular property stability constant (Kf1) of ML complex has been potentiometrically determined with different media and temperatures. Fe(III) and Cu(II) form very stable ML complexes with Kf1 11.02 and 9.17 respectively in 75% Ethanol-water medium at 25 °C, while Kf1 with Mn(II), Co(II), Ni(II) and Zn(II) range from 6.25 to 6.47. The formation of ML complexes is spontaneous and exothermic.Complexes of Co(II), Zn(II) and Cd(II) with 9-HOEtAde were synthesized and characterized by FTIR, NMR, thermal analysis and elemental analysis. The molecular structural property of Co(II) and Zn(II) complexes were studied by X-ray diffraction. Co(II) atoms in Co(acac)2(9-HOEtAde-N7)2.2H2O (1) displayed octahedral CoO4N2 coordination with four oxygen atoms of acetylacetonate ligands occupying the equatorial plane and two N7 atoms of 9-HOEtAde ligand in the axial plane. While Zn(9-HOEtAde-N7)2Cl2 (2) has a tetrahedral structure with π-π stacking. H-bonding in complexes (1) and (2) results in formation of chains and 3D-supramolecular array.CAM-B3LYP/6-31G(D)/LanL2DZ level of theory predicted the properties of tetrahedral Zn(9-HOEtAde-N7)2Cl2 (2) and the optimized structure was computed by DFT.Graphical abstractImage 1
       
  • A novel oxalate-based three dimensional polymorphs supramolecular
           compounds: Synthesis, spectroscopic characterization, magnetic and
           photocatalytic properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Rihab Dridi, Saoussen Namouchi Cherni, Farid Fettar, Nassira Chniba-Boudjada, Mohamed Faouzi ZidTwo metal complexes (C7H7N2)[Cr(C2O4)2(H2O)2]·2H2O (1) and (C7H7N2)3 [Cr(C2O4)3](H2C2O4)·3H2O (2), have been synthesized by self-assembly of a benzimidazole ligand and oxalic acid anion with chromium (III) as metal. The complexes (1) and (2) were characterized by single crystal X-ray diffraction, TG analysis and spectroscopy techniques. The molecular structure of complexes (1) and (2) appear to be a modular associate consisting of a complex anion containing trivalent Cr as the central atom, a bridging hydrogen oxalate anion, a monoprotonated benzimidazole acting as the counter-cation and water molecules. The atomic arrangement of complexes (1) and (2) can be described as inorganic layers of anionic chromium complex and water molecules between which organic cations (C7H7N2)+ are located. The crystal packing of complexes (1) and (2) is ensured by extensive O–H⋯O and N–H⋯O hydrogen bonds. In addition, the magnetic properties of the complex (1) were determined in the range 1.8–300 K showing a very weak antiferromagnetic interactions between Cr(III) centers with a little contribution of ZFS effect. Moreover, complexes (1) and (2) exhibit significant degradation of methylene blue (MB) under sunlight irradiation.Graphical abstractImage 1
       
  • Pyridyl anchor-assisted photoresponsiveness of
           4-(4-diethylaminophenylazo)pyridine on TiO2 surface
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Zhiqiao Chen, Lei Zhang, Kun Xu, Fengxi YuAbstractThe adsorption of organic molecule on metal oxide surfaces via a suitable anchoring group is important to realize various optoelectronic devices and surface switches. In this manuscript, we investigate the pyridyl anchor-assisted molecular adsorption of an azo dye 4-(4-diethylaminophenylazo)pyridine on TiO2 surface and the photoresponsiveness of the pyridyl anchoring-containing dye/TiO2 interfacial structure. The photoisomerization and photocurrent generation of the azo dye are activated on the TiO2 surface via the pyridyl anchor, which are otherwise unavailable when the azo dye is in the free form in the solution. The first-principles calculations elucidate the detailed nanoscopic structure and optoelectronic properties of the different molecule/TiO2 isomers. This manuscript highlights the potentials of the pyridyl anchor to substitute the traditional carboxylate group for the surface photoisomerization and photoresponsive studies, which can benefit various TiO2-incorporated surface switches and optoelectronic devices.
       
  • Synthesis, structure, cytotoxic and antioxidant properties of
           6-ethoxy-4-methylcoumarin
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): F.C. Celikezen, C. Orek, A.E. Parlak, K. Sarac, H. Turkez, Özlem Özdemir TozluCoumarins have a wide usage area in medicinal applications. It is known that the design and synthesis of new coumarin derivatives are performed to prepare new drugs in many laboratories. The aim of the study was to synthesize 6-ethoxy-4-methylcoumarin and detect its chemical and biological properties for the first time. 6-ethoxy-4-methylcoumarin was synthesized using Pechmann method. Atomic orbital (GIAO) 1H and 13C NMR chemical shift values in the ground state were calculated and Density Functional Method (DFT) was applied with the 6–311++G (d, p) basis set to determine chemical properties. 6-ethoxy-4-methylcoumarin was applied to cultured blood samples at various concentrations (10–400 mg/L) for determining biological activity. 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) and lactate dehydrogenase (LDH) release assays were used to evaluate cytotoxic effect. In addition, total antioxidant capacity (TAC) and total oxidative status (TOS) were examined to determine antioxidant properties. The results showed that theoretical vibrational frequencies and chemical shift values were close to experimental values. Moreover, 6-ethoxy-4-methylcoumarin showed a slight cytotoxic effect at dose of 200 mg/L and exhibited an antioxidant activity at 25 mg/L concentration without changing oxidative status at all of doses.Graphical abstractImage 101185
       
  • Optical and transport properties of double perovskite strontium bismuth
           vanadate
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): R.K. Parida, D.K. Pattanayak, Bhagyashree Mohanty, B.N. ParidaAbstractThe present study reports the optical and transport properties of polycrystalline vanadium based double perovskite. The material preparation, formation, symmetry, morphology and phase identification were carried out by respective solid solution casting, X-ray diffraction (XRD), scanning electron micrograph (SEM) image, energy dispersive spectroscopy (EDS), FTIR and RAMAN technique. The optical properties of the material were investigated by UV–Vis spectroscopy as well as photo luminescence (PL) spectra which reveal material may be useful for photo catalytic devices. For ferroelectric and transport behavior of the material were studied from dielectric, polarization and impedance measurement. It is observed from above measurement material have good room temperature dielectric constant (εr), polarization value (2Pr) and moderate transport properties with temperature for different device application.
       
  • 12-Tungstoboric acid (H5BW12O40) as an efficient Lewis acid catalyst for
           the synthesis of chromenopyrimidine-2,5-diones and
           thioxochromenopyrimidin-5-ones: Joint experimental and computational study
           
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Majid M. Heravi, Tayebeh Hosseinnejad, Mehrnoush Tamimi, Vahideh Zadsirjan, Masoud MirzaeiH5BW12O40 (BWA), Keggin-type heteropoly acid was employed as an effective, eco-friendly and reusable Lewis acid catalyst for the high yielding synthesis of chromenopyrimidine-2,5-diones and thioxochromenopyrimidin-5-ones via multicomponent reaction (MCR) of differently substituted benzaldehydes, urea/thiourea, and 4-hydroxycoumarin in refluxing water. The BWA catalyst could be recovered by a simple filtration and applied in three successive runs with no noticeable decrease in the yield. Interestingly, this catalyst structure pattern may act as useful model for the design and assembly of the functional molecule-based catalysts, especially in the field of molecular sieve materials. Moreover, thermochemical properties in the synthesis of title compounds were assessed using density functional theory (DFT) calculations.Graphical abstractImage 1
       
  • Green synthesis of garlic extract stabilized Ag@CeO2 composites for
           photocatalytic and sonocatalytic degradation of mixed dyes and
           antimicrobial studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Dasari Ayodhya, Guttena VeerabhadramNoble metals combined metal oxide composites have synergistic contributions to plasmonic catalysis caused by surface plasmon resonance (SPR) has emerged out as an impressive way for efficient light absorption and solar light conversion. In this work, a new approach was proposed to prepare noble metal-based CeO2 composites for the degradation of single and mixed dyes under natural sunlight and ultrasound irradiation. The garlic extract stabilized Ag@CeO2 composite was successfully prepared by Ag nanoparticles (NPs) on the surface of CeO2 via a simple method. The synthesized Ag NPs, CeO2 NPs, and Ag@CeO2 composite were investigated to determine its structural, optical, and morphological properties using powder XRD, UV–vis DRS, PL, BET, and TEM characterization techniques. The synthesized Ag@CeO2 composite having high purity and well-crystalline with an average size of ∼5–15 nm. The Ag@CeO2 composites were utilized as photocatalyst for degradation of single dyes (methylene blue; MB and methyl orange; MO) and mixed dye (MB + MO) under sunlight and ultrasound irradiation, showing the almost inclusive degradation of MB, MO and MB + MO in 30 min due to the fast electron transfer from Ag to CeO2 and surface plasmon resonance. In addition, they were also found to possess good stability and recyclability. Moreover, the possible photocatalytic mechanism for the degradation of dyes was also proposed. The synthesized Ag@CeO2 composites were further investigated for their antimicrobial activity towards several bacteria and fungi strains. The obtained results for Ag@CeO2 have displayed the significantly improved catalytic and antibacterial properties in comparison with pure CeO2 and Ag NPs.Graphical abstractImage 10201
       
  • Luminescence properties of SrAl2O4: Tb3+/ Bi3+ nanophosphors for photonic
           applications
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): B.C. Jamalaiah, N. MadhuThe Tb3+/Bi3+ co-doped SrAl2O4 (SAOTB) nanophosphors were synthesized and characterized through X-ray diffraction, Raman, photoluminescence excitation, emission and luminescence decay studies. The studied materials were crystallize into monoclinic phase with lattice parameters a = 8.4419 Å, b = 8.8217 Å, c = 5.1592 Å. The phase of SAOTB nanophosphors was confirmed by the Raman analysis. The morphological study reveals homogeneous distribution of particles of different size. The luminescence of Tb3+ ions was enhanced by the effective sensitization of Bi3+ ions when excited at 340 nm corresponding to Bi3+: 1S0 → 1P1 transition. The spectral overlap of Tb3+: 7F6 → 5G6 and Bi3+: 3P1 → 1S0 transition reveals the existence of transfer of energy from Bi3+ to Tb3+ ions. The SAOTB nanophosphors emit strong and enhanced green luminescence through Tb3+: 5D4 → 7FJ transitions when excited at 340 nm radiation. The colour perception and the luminescence quantum efficiency were investigated using the emission spectral profiles. The luminescence decay time of Tb3+: 5D4 emission level in SAOTB nanophosphors was found to be nearly 2.60 ms. The experimental results suggest that the SAOTB nanophosphors were more potential for display applications.Graphical abstractImage 1075
       
  • Prediction of correct intermolecular interactions in host-guest systems
           involving cyclodextrins
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Danylo A. Silva, Maria J. Xavier, José Diogo L. Dutra, Iara F. Gimenez, Ricardo O. Freire, Nivan B. da CostaAbstractInvestigations of intermolecular interactions are of great interest and many studies in this field focus on the use of theoretical computational chemistry. Commonly the systems of interest comprise molecules with hundreds of atoms, limiting the use of ab initio theoretical methods. In order to investigate the accuracy of different quantum chemical methods, a systematic study was carried out involving 15 inclusion complexes of α-cyclodextrin and 28 complexes of β-cyclodextrin. The accuracy of semiempirical methods in geometry prediction was evaluated in comparison to crystallographic data, with AM1 and PM3 showing the best results. Subsequently, the accuracy of semiempirical methods in predicting both geometry and interaction energy was studied using the results of DFT calculation as reference, with and without dispersion correction. The best method was B3LYP/6-31G(d,p) with D3 correction, followed by PM6 with D3 correction with similar accuracy. However, as the DFT method require a high computational cost for large systems, PM6-D3 is the method recommended for the systems studied here. The main conclusion is the need to develop a semiempirical method capable of correctly describing the interaction energy, which must correspond to an accurate geometry.
       
  • Adsorption and solidification of peppermint oil on microcrystalline
           cellulose surface: An experimental and DFT study
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Seyed Tahmoures Keshavarz, Mohammad Imani, Farhid FarahmandghaviMicrocrystalline cellulose, a well-known pharmaceutical excipient can adsorb and solidify peppermint oil i.e., a multi-component liquid model drug. The nature of intermolecular forces governing the process was a question. Peppermint oil adsorption kinetics on the microcrystalline cellulose surface was studied in liquid phase as a function of the adsorbate concentration. Peppermint oil components were separated and analyzed using gas chromatography-mass spectroscopy technique. Peppermint oil adsorption kinetics was best fitted to a pseudo-first order kinetic model showing equilibrium adsorption after 12 h. Adsorption of the constituent species was not occurred selectively considering the numerical values of the affinity constant (k1). A linear correlation was observed between the extent of the constituent species adsorption and their relative concentration in the mixture. The adsorption results were best described by Langmuir and Freundlich isotherms elucidating 110 mg.g-1 maximum peppermint oil adsorption and solidification capacity on microcrystalline cellulose surface. The significance of dispersive intermolecular interactions was concluded by analyzing Hansen solubility parameter for the pairs of adsorbent-adsorbate species. In silico molecular simulation of the interactions showed a linear correlation between binding energies and k1 values with a close-matching for all peppermint oil constituent species.Graphical abstractImage 1
       
  • Molecular docking and inhibitory effects of a novel cytotoxic agent with
           bovine liver catalase
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Somaye Shahraki, Maryam Saeidifar, Hojat Samareh Delarami, Houman KazemzadehThe synthesis of new metal complexes with fewer side effects than old drugs, such as cisplatin, is the major research pathway of many scientists. In this regard, the study of interactions between the promising complexes and certain targets such as enzymes is necessary. In this work, we reported the synthesis of Zn(II) complex of a novel bidentate Schiff base ligand, SBL, obtained from the condensation of 1-(2-aminoethyl)piperazine and 2,3-butanedione monoxime. The anticancer activities of [Zn(SBL)2]Cl2 complex against HT-116 cancer cell lines were studied by MTT assay and revealed that this complex can induce the cytotoxicity in the human colon cancer cell. The side effects of the prepared complex on the structure and catalytic function of bovine liver catalase (BLC) were evaluated by various spectroscopic and theoretical methods. The enzyme inhibition kinetics showed that Zn(II) complex inhibited catalase function by mixed-type inhibition. UV–Vis spectra, CD spectroscopy, synchronous, and 3D fluorescence confirmed the conformational changes in the structure of BLC in the presence of Zn complex. The fluorescence measurements showed that this complex quenches the intrinsic fluorescence of BLC via static quenching mechanism. The values of binding constants were obtained 2.68 × 104 M−1 and 0.48 × 104 M−1 at 300 and 310 K, respectively. The thermodynamic parameters revealed that the reaction of Zn(II) complex with catalase could proceed spontaneously through van der Waals forces and hydrogen bonds. The molecular docking simulation in the well coherent with kinetics results showed that there is one binding site for Zn(II) complex on BLC and this complex did not directly bind to the catalase active site.Graphical abstractImage 1
       
  • Synthesis, characterisation and energetic performance of insensitive
           energetic salts formed between picric acid and 2,3-diaminotoluene,
           2,4-diaminotoluene
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Nilgün Şen, Hasan Nazir, Nurunnisa Atҫeken, Karl S. Hope, Nurcan Acar, Orhan AtakolIn order to broaden the practical applications of Picric acid (PA), salts of PA have been synthesised with 2,3-diaminotoluene (PIC:23DAT), and 2,4-diaminotoluene (PIC:24DAT). This paper was discussed their synthesis, structural characterisation and supramolecular interactions. Salt formation was also observed between the phenolate hydrogen and amino groups. X-ray diffraction data shows that the salts are primarily formed through host-guest π … π stacking face-to-face interactions these non-covalent interactions govern the structures of the salts. Hirshfield surfaces and associated fingerprint plots of the salts were examined and the results indicated that the structures are stabilized by H⋯H, O⋯H, O⋯O, N⋯H and C⋯C (π … π) intermolecular interactions. The enthalpies of formation, the optimized structures, molecular total energies, frontier orbit energies, and HOMO-LUMO gaps of each compound were calculated using Gaussian 09; and detonation performances were calculated by using the EXPLO5 software. The results show that face-to-face π-stacking constructed by large π-bonded molecules and strong intra-intermolecular hydrogen bonding, which promote insensitivity in energetic materials. Both PIC:23DAT and PIC:24DAT salts were found to be approximately 80% less impact sensitive than PA.Graphical abstractImage 1
       
  • Cellulose grafted aliphatic polyesters: Synthesis, characterization and
           biodegradation under controlled conditions in a laboratory test system
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Fatima Ezahra Tabaght, Abderrahmane El Idrissi, Reda Bellaouchi, Abdeslam Asehraou, Mohamed Aqil, Soufian El Barkany, Abderrahim Benarbia, Nafea Achalhi, Abdesselam TahaniAbstractNovel biodegradable cellulose derivatives were synthesized using ‘grafting onto’ process. The synthesis method involves three-steps using 1, 6-hexamethylene diisocyanate as a coupling agent. This method improves the adhesion with cellulose fibers and was conducted using simple experimental techniques. In the first stage, the poly(butylene adipate) (PBA) and poly(ethylene adipate) (PEA) polyesters were synthesized by direct polycondensation reactions. Secondly, these polyesters were grafted onto cellulose surface using a simple addition reaction between the hydroxyl groups of the cellulose and the isocyanate groups existing at the ends of the polyester chains (precursors). The structure and physical properties of the prepared polymers were characterized by FTIR, NMR and TGA/DTG analysis. This simple and efficient strategy of synthesizing cellulose grafted aliphatic polyesters will provide new opportunities to fabricate many other biodegradable polymer composites.
       
  • Mechano-chemical syntheses of new cobalt(II) complexes of alkyl
           2-(pyridine-2yl-methylene) hydrazinecarboxylates: Crystal structures,
           spectroscopic and photoluminescence properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Subramani Sathiyakumar, Pitchai Selvam, Sudhadevi Antharjanam, Furuck Lukmanul Hakkim, Krishnan Srinivasan, William T.A. HarrisonNew cobalt (II) complexes of general formula [Co(L) (NO3) (H2O)2]·NO3 (L = methyl 2-(pyridine-2yl-methylene) hydrazinecarboxylate, C8H9N3O2 (2-PYMC) (1) and ethyl 2-(pyridine-2yl-methylene) hydrazinecarboxylate, C9H11N3O2 (2-PYEC) (2), have been synthesized and characterized by elemental analysis, UV–vis, IR, and photoluminescence measurements. The crystal structures of 1 and 2 reveal the presence of CoN2O5 pentagonal-bipyramidal coordination polyhedra in each complex: the basal plane consists of an N, N, O-tridentate 2-PYMC/2-PYEC ligand and a chelating nitrate anion and the axial sites are occupied by water molecules. The crystal structures are consolidated by O–H⋯O and C–H⋯O hydrogen bonds.Graphical abstractImage 1
       
  • Copper complexes of pyrazolone-based Schiff base ligands: Synthesis,
           crystal structures and antibacterial properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Elaheh Bechari Poormohammadi, Mahdi Behzad, Zeinab Abbasi, Shakiba Darvish Alipour AstanehTwo new Cu(II) Schiff base complexes were synthesized and characterized. The corresponding NO type bidentate Schiff base ligands were synthesized from the condensation of 2,5-dimethylaniline (HL1) or 3,5-dimethylaniline (HL2) with 4-acetyl-3-methyl-1-phenyl-5-pyrazolone. Another bidentate Schiff base ligand (HL3) was also synthesized from the condensation of Prop-2-en-1-amine (allylamine) with 4-acetyl-3-methyl-1-phenyl-5-pyrazolone but all attempts to synthesize the corresponding Schiff base complex failed. The ligands and complexes were characterized by general spectroscopic techniques including 1HNMR, IR, UV–Vis spectroscopy as well as elemental analysis. Crystal structure of one of the complexes, [Cu(L1)2] was determined. Antibacterial potential of these ligands and complexes were tested against four bacteria, namely Escherichia coli (G−), Pseudomonas aeruginosa (G−), Staphylococcus aureus (G+) and Bacillus subtilis (G+). The ligands and complexes showed considerable antibacterial activity against both gram-positive and gram-negative bacteria. The ligands almost showed higher antibacterial activity than the corresponding complexes.Graphical abstractAntibacterial properties of a series of acylpyrazolone based Schiff base ligands and Cu(II) complexes were studied and good antibacterial activity was observed.Image 1
       
  • Molecular interactions in the binary solutions of methyl cellosolve with
           chlorobenzene: Spectroscopic and dielectric studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): A. Mahendraprabu, N.K. Karthick, P.P. Kannan, T. Sangeetha, A.C. Kumbharkhane, G. ArivazhaganH-bond interactions of methyl cellosolve (MCS) with chlorobenzene (CBZ) have been studied using FTIR spectroscopy and Time Domain Reflectometry (TDR) studies. (MCS)O−H⋯π(CBZ) , (MCS)O−H⋯Cl(CBZ) , (MCSCH2)C−H⋯π(CBZ), (MCSCH2)C−H⋯Cl(CBZ) H-bond interactions may exist in the MCS-CBZ binary solutions. The shifts in the ν(C−O−C) and ν(C−OH) stretching bands on mixing are due to the proximity effect arising out of the involvement of both CH2 and O−H hydrogens, respectively, in heteromolecular H-bond. The role of molecular interactions and molar volumes become relatively less significant in determining the relaxation times of the solutions. Instead, the viscosity plays a more dominant role in determining the relaxation times of the MCS-CBZ solutions. Parallel orientation of dipoles is favoured in MCS rich solutions while in CBZ rich solutions the dipoles prefer antiparallel alignment. The excess values of the dielectric constant and free energy show negative and positive deviations, respectively.Graphical abstractImage 1
       
  • A novel 3-((5-methylpyridin-2-yl)amino)isobenzofuran-1(3H)-one: Molecular
           structure describe, X-ray diffractions and DFT calculations, antioxidant
           activity, DNA binding and molecular docking studies
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Z.T. Yılmaz, H. Yasin Odabaşoğlu, P. Şenel, V. Adımcılar, T. Erdoğan, A.D. Özdemir, A. Gölcü, M. OdabaşoğluIn this work, the structure of a novel phthalide derivative, 3-((5-methylpyridin-2-yl) amino) isobenzofuran-1(3H)-one, was analyzed both experimentally and theoretically by X-ray single crystal diffraction technique, IR spectroscopy, and quantum chemical computation. The X-ray diffraction analysis indicates that 3-((5-methylpyridin-2-yl) amino) isobenzofuran-1(3H)-one crystallizes in a monoclinic space group P21/n with unit-cell parameters a = 8.0712(7) Å, b = 6.6762(4) Å, c = 23.005(2) Å, β = 98.813(7)° and Z = 4. Additionally, DFT method at B3LYP level by using the hybrid functional with 6-311G (d, p) basis set have been used in the geometry optimizations and vibrational frequencies calculations of the title compound in ground state. The geometrical parameters obtained from XRD studies and the calculated values are in good agreement to each other. In addition, the electronic properties, such as HOMO and LUMO energies, and thermodynamic properties were calculated with the same method. The chemical reactivity estimation, the molecular electrostatic potential (MEP) surface map and PES scan of the related molecule were investigated with theoretical calculations at the B3LYP/6-31þG(d,p) and B3LYP/3-21G levels, respectively. The Folin-Ciocalteu’s method have been used to determine the total phenolic (TP) content of the compound under study and it was found to be 0.14 (±0.0) mg gallic acid equivalents (GAE)/g. Antioxidant activities were evaluated by 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical scavenging activity and ferric reducing anti-oxidant power assay (FRAP). Metal chelating assay was based on the measurement of iron-ferrozine absorbance at 562 nm. The DNA binding affinity for double strain fish sperm DNA (dsFSDNA) was investigated by electronic absorption titration, thermal denaturation measurement and viscosity techniques which indicate that the title compound binds to dsFSDNA by minor groove and has a binding constant of 9.59 × 104. Additionally, in molecular docking studies, it has been observed that the lowest energy docking pose binds to minor groove of DNA and 1-DNA complex has been stabilized by several hydrogen bonds. The binding affinity of the lowest energy docking pose was found to be −8.3 kcal/mol.Graphical abstractImage 1
       
  • Synthesis and investigations for white LED material: VO2+ doped Calcium
           Cadmium phosphate hydrate nanophosphor
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): T. Rajyalakshmi, Sk Johny Basha, V. Khidhirbrahmendra, U. S.Udayachandran Thampy, R.V.S.S.N. RavikumarVanadyl ion doped Calcium Cadmium Phosphate Hydrate (CaCdPH–V) was synthesized by conventional SSR (solid state reaction) method. The powdered synthesized sample was characterized by PXRD, SEM with EDAX, UV–vis (optical) absorption, EPR and FTIR techniques. XRD studies confirm hexagonal crystal structure for VO2+ doped Calcium Cadmium phosphate hydrate with the crystallite size 42 nm. The crystalline size and lattice strain are also evaluated by the Williamson-Hall (W–H) analysis. The absorption spectrum of CaCdPH–V is recorded from 200 to 1200 nm. From the optical spectrum three bands are identified at 815 (12267 cm−1), 611 (16362 cm−1) and 453 nm (22069 cm−1). Room temperature Electron Paramagnetic Resonance spectrum of V4+ has depicted broad symmetric lines. From EPR & optical spectral studies confirmed that VO2+ ions is tetragonal compression with octahedral symmetry. The molecular orbital coefficients and different EPR parameters are also evaluated. CIE color coordinate is estimated from emission data by MATLAB program is found to be (0.3164, 0.3056) which is in white region. FTIR spectrum reveals the information about various characteristic bands of phosphate and OH bands of the prepared powder phosphate material. The novelty of the present work is to understand the site symmetry, colour purity of prepared sample and to make a suitable candidate for light emitting devices application point of view.Graphical abstractThe EPR spectrum of 0.01 mol% of VO2+ doped Calcium Cadmium phosphate Hydrate nanophosphors is shown above Figure. An octahedral site with a tetragonal compression would give the values of g‖
       
  • A rhodamine-based fluorescent sensor for selective detection of Cu2+ in
           aqueous media: Synthesis and spectroscopic properties
    • Abstract: Publication date: 5 April 2020Source: Journal of Molecular Structure, Volume 1205Author(s): Fasil Abebe, Pierce Perkins, Roosevelt Shaw, Solomon TadesseTwo new chemosensors, rhodamine B derivative bearing 3-formyl-6-nitrochromone (L1) and 3-formyl-6-methylchromone (L2) units were designed and synthesized using microwave irradiation for the selective detection of Cu2+ in aqueous media. Copper triggers the formation of highly fluorescent ring-open spirolactam. The fluorescence intensity was remarkably increased upon the addition of Cu2+ within a minute, while the other metal ions caused no significant effect. More importantly, the resulting complexes can be used as a reversible fluorescence sensor for CN−. The recognition ability of the sensors was investigated by fluorescence titration, Job’s plot, 1H NMR spectroscopy and density functional theory (DFT) calculations.Graphical abstractImage 1
       
  • The synthesis of −1, −3, −5, −7, −8 aryl substituted
           boron-dipyrromethene chromophores: Nonlinear optical and photophysical
           characterization
    • Abstract: Publication date: Available online 7 January 2020Source: Journal of Molecular StructureAuthor(s): Gökhan Sevinç, Betül Küçüköz, Ayhan Elmalı, Mustafa HayvalıA convenient protocol enabled the synthesis of novel Arylated Borondipyrromethene (BODIPY) compounds was applied that synthesis yields found to be higher than classical alkyl substituted analogues. The nonlinear properties of the target molecules were investigated systematically in terms of aryl substitution to the pyrrole side and the meso substitution on the indacene core. It was found that, −3, −5 positions of the indacene core are effective positions for charge transfer, which is essential for two photon absorption (TPA). The greatest two photon cross section (TPCS) value (178 GM) is obtained for BDP3 compound, while TPCS value of BDP4 compound is 27 GM at near infrared wavelength (800 nm). Arylated chromophores exhibited the broader red-shifted absorption and fluorescence bands with higher stokes shifts with regard to reference Borondipyrromethene compound (4,4′-difluoro-8-phenyl-1,3,5,7-tetramethyl-4-bora-3a, 4a-diaza-s-indacene, TMB). Our results are helpful for designing new photosensitizers and for applications in the study of the molecular photochemistry.Graphical abstractImage 1
       
  • Theoretically and experimentally exploring the corrosion inhibition of N80
           steel by pyrazol derivatives in simulated acidizing environment
    • Abstract: Publication date: Available online 6 January 2020Source: Journal of Molecular StructureAuthor(s): Ambrish Singh, K.R. Ansari, M.A. Quraishi, Savas KayaAcidizing is the important process used in petroleum industry for oil well stimulation. Here, we are exploring the green synthesis of 4,4'-((4-methoxyphenyl)methylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) (PZ-1) and 4,4'-((4-nitrophenyl)methylene)bis(3-methyl-1-phenyl-1H-pyrazol-5-ol) (PZ-2) under ultrasonic irradiation and its potential application for N80 steel corrosion mitigation in 15% HCl. The corrosion inhibition investigation was performed by open circuit potential (OCP), electrochemical impedance spectroscopy (EIS), linear polarization (LPR), potentiodynamic polarization (PDP), electrochemical frequency modulation (EFM), and electrochemical frequency modulation trend (EFMT), weight loss, scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), density functional theory (DFT) and molecular dynamics (MD). The EIS and PDP results suggests an increased impedance in presence of PZs and mixed nature of inhibitor action respectively. The protection efficiency (ɳ%) are 98.4% (PZ-1) and 94.3% (PZ-2). The results of EFMT provides the average decrease in corrosion rate and corrosion current density (icorr). The surface analysis suggests a protective layer of PZs. DFT analysis reveals that PZ-1 with lower value of ΔE acts as a better inhibitor compared to PZ-2. MD study supports a stronger binding and interaction ability of PZ-1 than PZ-2.Graphical abstractImage 1
       
  • Synthesis of glucosamine derivative with double caffeic acid moieties at
           N– and 6-O-positions for developments of natural based materials
    • Abstract: Publication date: Available online 6 January 2020Source: Journal of Molecular StructureAuthor(s): Kenta Yamatani, Ryo Kawatani, Hiroharu AjiroGlucosamine derivatives with double caffeic acid moieties were synthesized for developments of natural based materials. Caffeic acids were introduced to glucosamine derivatives through the synthesis roots as protection and de-protection reactions. Firstly, the silyl groups and tert-butoxycarbonyl groups were selected for the protection of each hydroxyl group and amino group. The designed glucosamine derivative showed reactivity of the double bonds, which was confirmed by UV spectra. Photoresponsivity was observed both in solution and heterogeneous suspension. The oligomerization was also confirmed in water suspension. The solubility and thermal stability were changed after the UV irradiation. This results show the potential of great progress a natural based material development.Graphical abstractImage 1
       
  • Spectral, DFT/B3LYP and molecular docking analyses on ethyl
           2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)pent-4-enoate
    • Abstract: Publication date: Available online 6 January 2020Source: Journal of Molecular StructureAuthor(s): Yusuf Sert, Sanae Lahmidi, Mohamed El Hafi, Halil Gökce, El Mokhtar Essassi, Abdelaziz Ejjoumamany, Joel T. MagueIn this paper, the compound ethyl 2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)pent-4-enoate was synthesized and identified by FT-IR,1H and 13C NMR, UV–Vis. And single crystal x-ray diffraction. In addition, theoretical calculations including an optimized structure analysis, Hirshfeld surface analysis, High Occupied Molecular Orbital (HOMO)-Lowest Unoccupied Molecular Orbital (LUMO) analysis, UV–Vis. parameters with an IEFPCM solvent model, MEP-Molecular Electrostatic Potential and NLO-Non-Linear Optical properties and a molecular docking analysis were carried out. All theoretical computations were performed by the DFT/B3LYP functional and the 6–311++G(d,p) basis set in the ground state. The assignments of calculated infrared vibrational frequencies were performed using the VEDA4 software for the first time through the optimized structure's chk*. and the experimental and theoretical data are in good agreement. In addition, molecular docking studies between ethyl 2-(5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)pent-4-enoateand the c-MET protein (PDB ID: 5EOB) were performed by using the AutoDock Vina program. The title molecule appears to be a good inhibitor for cancer treatment due to its binding energy and ability to adhere to the active sites of the protein.Graphical abstractImage 1
       
 
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