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  Subjects -> CHEMISTRY (Total: 765 journals)
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CHEMISTRY (530 journals)            First | 1 2 3 4 5 6 | Last

Journal of Heterocyclic Chemistry     Hybrid Journal   (Followers: 5)
Journal of Immunoassay and Immunochemistry     Hybrid Journal   (Followers: 3)
Journal of Inclusion Phenomena and Macrocyclic Chemistry     Hybrid Journal   (Followers: 2)
Journal of Inorganic Biochemistry     Hybrid Journal   (Followers: 3)
Journal of Labelled Compounds and Radiopharmaceuticals     Hybrid Journal   (Followers: 1)
Journal of Macromolecular Science, Part A: Pure and Applied Chemistry     Hybrid Journal   (Followers: 4)
Journal of Mass Spectrometry     Hybrid Journal   (Followers: 20)
Journal of Materials Chemistry A : Materials for Energy and Sustainability     Full-text available via subscription   (Followers: 22)
Journal of Materials Chemistry B : Materials for Biology and Medicine     Full-text available via subscription   (Followers: 5)
Journal of Materials Chemistry C : Materials for Optical, Magnetic and Electronic Devices     Full-text available via subscription   (Followers: 6)
Journal of Materials Research     Full-text available via subscription   (Followers: 9)
Journal of Mathematical Chemistry     Hybrid Journal   (Followers: 4)
Journal of Medicinal Chemistry     Full-text available via subscription   (Followers: 142)
Journal of Membrane Science     Hybrid Journal   (Followers: 9)
Journal of Modern Chemistry & Chemical Technology     Full-text available via subscription   (Followers: 1)
Journal of Molecular Catalysis A: Chemical     Hybrid Journal   (Followers: 2)
Journal of Molecular Graphics and Modelling     Hybrid Journal   (Followers: 3)
Journal of Molecular Liquids     Hybrid Journal   (Followers: 3)
Journal of Molecular Modeling     Hybrid Journal   (Followers: 3)
Journal of Molecular Recognition     Hybrid Journal  
Journal of Molecular Spectroscopy     Hybrid Journal   (Followers: 6)
Journal of Molecular Structure     Hybrid Journal   (Followers: 3)
Journal of Nanostructure in Chemistry     Open Access   (Followers: 5)
Journal of Natural Gas Chemistry     Full-text available via subscription   (Followers: 2)
Journal of Nepal Chemical Society     Open Access  
Journal of Nucleic Acids Investigation     Open Access   (Followers: 2)
Journal of Ocean University of China (English Edition)     Hybrid Journal   (Followers: 2)
Journal of Organometallic Chemistry     Hybrid Journal   (Followers: 12)
Journal of Photochemistry and Photobiology A: Chemistry     Hybrid Journal   (Followers: 4)
Journal of Photochemistry and Photobiology C: Photochemistry Reviews     Full-text available via subscription   (Followers: 4)
Journal of Polymer Science Part A: Polymer Chemistry     Hybrid Journal   (Followers: 148)
Journal of Polymers     Open Access   (Followers: 1)
Journal of Porphyrins and Phthalocyanines     Hybrid Journal   (Followers: 2)
Journal of Pure and Applied Chemistry Research     Open Access  
Journal of Raman Spectroscopy     Hybrid Journal   (Followers: 9)
Journal of Saudi Chemical Society     Open Access  
Journal of Solid State Chemistry     Hybrid Journal   (Followers: 12)
Journal of Solution Chemistry     Hybrid Journal  
Journal of Structural Chemistry     Hybrid Journal  
Journal of Sulfur Chemistry     Hybrid Journal   (Followers: 2)
Journal of Superhard Materials     Hybrid Journal   (Followers: 1)
Journal of Surfactants and Detergents     Hybrid Journal   (Followers: 5)
Journal of Systems Chemistry     Open Access   (Followers: 1)
Journal of Taibah University for Science     Open Access  
Journal of the American Chemical Society     Full-text available via subscription   (Followers: 226)
Journal of the American Society for Mass Spectrometry     Hybrid Journal   (Followers: 15)
Journal of the American Society of Brewing Chemists     Full-text available via subscription   (Followers: 1)
Journal of the Bangladesh Chemical Society     Open Access  
Journal of the Chilean Chemical Society     Open Access   (Followers: 2)
Journal of the Iranian Chemical Society     Hybrid Journal   (Followers: 1)
Journal of the Korean Society for Applied Biological Chemistry     Hybrid Journal   (Followers: 1)
Journal of the Mexican Chemical Society     Open Access   (Followers: 1)
Journal of Theoretical and Computational Chemistry     Hybrid Journal   (Followers: 7)
Journal of Theoretical Chemistry     Open Access  
Journal of Wood Chemistry and Technology     Hybrid Journal   (Followers: 7)
JPC - Journal of Planar Chromatography - Modern TLC     Full-text available via subscription   (Followers: 6)
Jurnal Penelitian Sains (JPS)     Open Access  
Jurnal Teknologi Informasi     Open Access   (Followers: 3)
Kinetics and Catalysis     Hybrid Journal   (Followers: 3)
Korea-Australia Rheology Journal     Hybrid Journal  
Langmuir     Full-text available via subscription   (Followers: 35)
Latvian Journal of Chemistry     Open Access   (Followers: 1)
Lebensmittelchemie     Hybrid Journal   (Followers: 1)
Lipid Insights     Open Access   (Followers: 1)
Luminescence     Hybrid Journal   (Followers: 1)
Macromolecular Materials & Engineering     Hybrid Journal   (Followers: 4)
Macromolecular Rapid Communications     Hybrid Journal   (Followers: 4)
Macromolecular Research     Hybrid Journal  
Macromolecular Symposia     Hybrid Journal  
Macromolecular Theory and Simulations     Hybrid Journal  
Macromolecules     Full-text available via subscription   (Followers: 31)
Magnetic Resonance in Chemistry     Hybrid Journal   (Followers: 4)
Main Group Chemistry     Hybrid Journal  
Marine Chemistry     Hybrid Journal   (Followers: 4)
Marine Drugs     Open Access   (Followers: 4)
MATEC Web of Conferences     Open Access  
Materials Characterization     Hybrid Journal   (Followers: 21)
Materials Horizons     Full-text available via subscription  
Materials Research Bulletin     Hybrid Journal   (Followers: 15)
Materials Science Monographs     Full-text available via subscription   (Followers: 1)
Materials Science-Poland     Hybrid Journal  
Materials Sciences and Applications     Open Access   (Followers: 4)
MedChemComm     Full-text available via subscription   (Followers: 4)
Medicinal Chemistry Research     Hybrid Journal   (Followers: 10)
Metallography, Microstructure, and Analysis     Hybrid Journal   (Followers: 1)
Metallomics     Full-text available via subscription  
Micro and Nano Systems Letters     Open Access   (Followers: 1)
Microchimica Acta     Hybrid Journal   (Followers: 1)
Microporous and Mesoporous Materials     Hybrid Journal   (Followers: 3)
Modern Research in Catalysis     Open Access   (Followers: 2)
Molbank     Open Access  
Molecules     Open Access   (Followers: 3)
Molecules and Cells     Hybrid Journal   (Followers: 1)
Monatshefte für Chemie - Chemical Monthly     Hybrid Journal   (Followers: 3)
Moscow University Chemistry Bulletin     Hybrid Journal   (Followers: 2)
MRS Bulletin     Full-text available via subscription   (Followers: 5)
MRS Online Proceedings     Full-text available via subscription   (Followers: 1)
Nachrichten aus der Chemie     Full-text available via subscription   (Followers: 1)
Nano Reviews     Open Access   (Followers: 15)
Nanomaterials and the Environment     Open Access  

  First | 1 2 3 4 5 6 | Last

Journal Cover Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy
   [9 followers]  Follow    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
     ISSN (Print) 1386-1425
     Published by Elsevier Homepage  [2563 journals]   [SJR: 0.567]   [H-I: 58]
  • Molecular structure (monomeric and dimeric) and hydrogen bonds in 5-benzyl
           2-thiohydantoin studied by FT-IR and FT-Raman spectroscopy and DFT
           calculations
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Vipin Deval , Amit Kumar , Vineet Gupta , Anamika Sharma , Archana Gupta , Poonam Tandon , Ko-Ki Kunimoto
      In the present work the structural and spectral characteristics of 5-benzyl-2-thiohydantoin (5-BTH) have been studied by methods of infrared, Raman spectroscopy and quantum chemistry. Electrostatic potential surface, optimized geometry, harmonic vibrational frequencies, infrared intensities and activities of Raman scattering were calculated by density functional theory (DFT) employing B3LYP with complete relaxation in the potential energy surface using 6-311G++(d,p) basis set. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The 13C nuclear magnetic resonance (NMR) chemical shifts of the molecule are calculated by the gauge independent atomic orbital (GIAO) method and compared with experimental results. UV–vis spectrum of the compound was recorded in methanol solvent. The TD-DFT calculations have been performed to explore the influence of electronic absorption spectra in the gas phase, as well as in solution environment using PCM and 6-311++G(d,p) basis set. In addition, the thermodynamic properties of the compound were calculated at different temperatures and corresponding relations between the properties and temperature were also studied.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • The study of hydrogen bonding and π⋯π interactions in
           phenol⋯ethynylbenzene complex by IR spectroscopy
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Danijela Vojta , Mario Vazdar
      Weak hydrogen bonds between phenol and ethynylbenzene in tetrachloroethene were explored by using FTIR spectroscopy. Association constants (Kc ) were determined by high dilution method at two temperatures, 20°C and 26°C, and they are, respectively, 0.54±0.09mol−1 dm3 and 0.36±0.08mol−1 dm3. The position of ethynylbenzene stretching band, when in hydrogen bonding complex with phenol (CC⋯), is proposed to be governed by the interplay of OH⋯π (CC moiety or phenyl ring of ethynylbenzene) and π⋯π (phenyl ring of phenol⋯CC moiety or phenyl ring of ethynylbenzene) interactions. This conclusion is supported by the findings on the complex between ethanol and ethynylbenzene; in the latter, CC⋯ stretching band is shifted to the higher wavenumbers, as expected when ethynylbenzene interacts with hydrogen bond donor. Geometries and energies of the presumed complexes, as well as their vibrational spectra, are predicted by using ab initio calculations. The spectroscopic and thermodynamic data obtained here offer the missing pieces in the present picture of migration of H-atom of phenol OH group between competing hydrogen bond accepting centers on ethynylbenzene.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Portable evanescent wave fiber biosensor for highly sensitive detection of
           Shigella
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Rui Xiao , Zhen Rong , Feng Long , Qiqi Liu
      A portable evanescent wave fiber biosensor was developed to achieve the rapid and highly sensitive detection of Shigella. In this study, a DNA probe was covalently immobilized onto fiber-optic biosensors that can hybridize with a fluorescently labeled complementary DNA. The sensitivity of detection for synthesized oligonucleotides can reach 10−10 M. The surface of the sensor can be regenerated with 0.5% sodium dodecyl sulfate solution (pH 1.9) for over 30 times without significant deterioration of performance. The total analysis time for a single sample, including the time for measurement and surface regeneration, was less than 6min. We employed real-time polymerase chain reaction (PCR) and compared the results of both methods to investigate the actual Shigella DNA detection capability of the fiber-optic biosensor. The fiber-optic biosensor could detect as low as 102 colony-forming unit/mL Shigella. This finding was comparable with that by real-time PCR, which suggests that this method is a potential alternative to existing detection methods.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Investigation on the inclusion interaction of 4-sulfonatocalix[n]arenes
           with 1-(4-nitrophenyl)piperazine
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Yongbin Zhang , Jianbin Chao , Shuhui Zhao , Penghao Xu , Hongfang Wang , Zhiqiang Guo , Diansheng Liu
      The inclusion behaviors of 4-Sulfonatocalix[n]arenes (SCXn) (n=4, 6, 8) with 1-(4-nitrophenyl)piperazine (NPP) were investigated by UV spectroscopy and fluorescence spectroscopy at different pH values (pH=3.05, 6.50, 8.40). The UV absorption and fluorescence intensity of NPP remarkably increased in presence of SCXn revealing formation of the inclusion complexes between NPP and SCXn. Moreover, the formation constants (K) of inclusion complexes were also determined by the non-linear fitting method, and the obtained data showed that the formation constants decreasedgradually with the increasing of the pH value. When the pH value was 3.05, the formation constant of NPP with SCX8 reached a maximum of 1.7×107 Lmol−1. The stoichiometric ratio was verified to be 1:1 by the continuous variation method. Meanwhile FT-IR and DSC analysis also indicated that NPP could form the inclusion complex with SCXn. In order to explore the inclusion mechanism of NPP with SCXn, 1H NMR and molecular modeling studies were carried out and experimental results showed that the part of benzene ring of NPP penetrated into the hydrophobic cavity of SCXn.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Naked-eye detection of biologically important anions by a new chromogenic
           azo-azomethine sensor
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Khatereh Rezaeian , Hamid Khanmohammadi
      A new chromogenic azo-azomethine sensor, containing active phenolic sites, has been designed and synthesized via condensation reaction of N,N,N′,N′-tetrakis(2-aminoethyl)-2,2-dimethyl propane-1,3-diamine with 1-(3-formyl-4-hydroxyphenylazo)-4-nitrobenzene. The anion recognition ability of the synthesized receptor was evaluated using UV–Vis spectroscopy and 1H NMR technique. The anion recognition studies exhibited that the receptor acts as a sensor for biologically important anions such as F−, AcO− and H2PO4 − over other anions. The binding stoichiometry between sensor and anions was found to be 1:2. 1H NMR experiment revealed that sensor recognizes anions via H-bonds and subsequent deprotonation to elicit a vivid color change. Interestingly, the sensory system not only let for the naked eye detection without any spectroscopic instrumentation but also helped to discriminate between anions.
      Graphical abstract image Highlights A new chromogenic azo-azomethine sensor has been synthesized. The anion recognition studies exhibited that the receptor acts as a sensor for biologically important anions such as F−, AcO− and H2PO4 − over other anions. Interestingly, the sensory system not only let for the naked eye detection without any spectroscopic instrumentation but also helped to discriminate between anions.

      PubDate: 2014-06-18T17:25:07Z
       
  • Structural, morphological and optical studies of l-cysteine modified
           silver nanoparticles and its application as a probe for the selective
           colorimetric detection of Hg2+
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): M. Nidya , M. Umadevi , Beulah J.M. Rajkumar
      We report an extensive study on the evolution of a highly facile, selective colorimetric probe for Hg2+ detection using cysteine modified silver nanoparticles. The nanoparticles are stable in a basic medium and the Surface Enhanced Raman Spectrum (SERS) reveal that the cysteine is bound to the Ag surface through the thiolate moiety with the charged carboxylate group pointing outwards in a morphology that lends itself to sensor applications. In the presence of Hg2+, the absorption peak is quenched resulting in a drastic colour change. The sensor displays high selectivity to Hg2+ over other metallic ions.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Estimation of Eu3+ in bulk uranium by ligand sensitized fluorescence in
           dimethyl sulphoxide
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): S. Maji , Satendra Kumar , K. Sankaran
      Ligand sensitized fluorescence of europium ion using thenoyltrifluoroacetone (TTA) as a sensitizing ligand and dimethyl sulphoxide (DMSO) as a solvent is studied for the first time. TTA ligand enhances the fluorescence of Eu3+ by a factor of 40000 in DMSO. Linearity is obtained for a concentration range of 0.076–7.6ng/mL of Eu3+ with a detection limit of 7.6pg/mL. The quenching of Eu3+-TTA fluorescence by uranium matrix was studied in different solvents and found to be less in DMSO. Consequently, estimation of Eu3+ in a large excess of uranium becomes a possibility without the need to separate uranium from the solution, which has been demonstrated in this paper. Satisfactory results are obtained when Eu3+ is present at a concentration of 0.6μg/g in uranium.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Optimization of β-cyclodextrin cross-linked polymer for monitoring of
           quercetin
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Xiashi Zhu , Wenhui Ping
      A novel method for the separation/analysis of quercetin was described, which was based on the investigation of the inclusion interactions of β-cyclodextrin cross-linked polymer (β-CDCP) with quercetin (Qu) and the adsorption behavior of Qu on β-CDCP. The inclusion interaction of β-CDCP with Qu was studied through FTIR, TGA and 13C NMR. Under the optimum conditions, the preconcentration factor of the proposed method was approximately 8.8, the β-CDCP could be used repeatedly for 30 times and offered better recovery. The linear range, limit of detection (LOD) and the relative standard deviation (RSD) was found to be 0.10–12.0μgmL−1, 4.6ngmL−1 and 3.10% (n =3, c =2.0μgmL−1) respectively. This technique had been successfully applied to the determination of Qu in real samples.
      Graphical abstract image Highlights There were some obvious changes of characteristic absorption peaks for the β-CDCP−Qu: (1) σ CC peak (1612cm−1) in β-CDCP−Qu vanished; the width of peak at 3390cm−1 was larger in β-CDCP−Qu; which was demonstrated that the aromatic part in Qu was included into the hydrophobic cavity of β-CDCP. (2) The intensity of σ COH peaks at 1333cm−1 and 1244cm−1 in β-CDCP−Qu were much higher than that of β-CDCP, it was probably attributed to the fact that the hydrogen bond interactions played a crucial role in the inclusion of β-CDCP−Qu.

      PubDate: 2014-06-18T17:25:07Z
       
  • Raman bandshape analysis on CH and CSC stretching modes of dimethyl
           sulfoxide in liquid binary mixture: Comparative study with
           quantum-chemical calculations
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Ganesh Upadhyay , Th. Gomti Devi
      The interacting nature of dimethyl sulfoxide (DMSO) in binary mixtures has been carried out on CH and CSC stretching modes of vibration using chloroform (CLF), chloroform-d (CLFd), acetonitrile (ACN) and acetonitrile-d3 (ACNd) solvents. Peak frequencies of both the stretching modes show blue shift with the increase in solvent concentration. Variation of Raman bandwidth with the solvent concentration was discussed using different mechanisms. Ab initio calculation for geometry optimization and vibrational wavenumber calculation have been performed on monomer and dimer structures of DMSO to explain the experimentally observed Raman spectra. Theoretically calculated values are found in good agreement with the experimental results. Vibrational and reorientational relaxation times have been studied corresponding to solvent concentrations to elucidate the interacting mechanisms of binary mixtures.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Linear and nonlinear optical, mechanical, electrical and surface studies
           of a novel nonlinear optical crystal – Manganese mercury thiocyanate
           (MMTC)
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): R. Josephine Usha , P. Sagayaraj , V. Joseph
      The highly efficient nonlinear optical single crystal of manganese mercury thiocyanate has been grown from slow evaporation solvent technique. The second harmonic generation and optical transmittance of the grown crystal are studied by Kurtz and Perry powder technique and spectroscopic absorbance spectrum. Mechanical behaviour is analyzed using Vickers microhardness test. The dielectric response of the grown crystal is studied as a function of the temperature and the results are discussed. Further, electronic properties such as plasma energy, Penngap, Fermi energy and electronic polarizability are evaluated. Third order nonlinear optical studies are performed using by single beam Z-scan technique using Nd:YAG laser and parameters such as nonlinear refractive index n 2, absorption co-efficient β and nonlinear optical susceptibility χ (3) are evaluated for the grown crystal. The surface of the grown crystal is analyzed with field emission scanning electron microscope and atomic force microscope analyses.
      Graphical abstract image Highlights It is observed from the AFM image that crystal surface possesses valleys and hillocks. It is well known that a large number of peaks and valleys in an image significantly affect the average roughness (Sa ) and root mean square (Sq ) values.

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis, photophysical and thin-film self-assembly properties of novel
           fluorescent molecules with carbon–carbon triple bonds
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Qingfen Niu , Hongjian Sun , Xiaoyan Li
      Three novel fluorescent molecules with carbon–carbon triple bonds 2TBEA, 2TBDA and TEPEB are successfully designed and synthesized. Their thermal, photophysical, electrochemical, electronic and thin-film self-assembly properties were characterized. Three dyes showed typical photoluminescence (PL) emission behaviors, the PL intensities firstly increased and then decreased with gradually decreasing concentration. The appealing fluorescence properties indicated that three dyes could be used as good fluorescent materials. Additionally, the thin-film self-assembly behaviors of three dyes were also investigated. The microstructures of their optical microscopy (OM) images exhibited high flexibility. Furthermore, SEM and AFM surface morphology of these self-assembly nanostructures revealed that three well-defined long-range order of rod-like and tube-like self-assembly systems exhibited interesting morphology properties. Therefore, three compounds may be of great interest for the development of organic thin-film materials.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Spectroscopic study of the recognition of 2-quinolinone derivative on
           mercury ion
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Yongbin Zhang , Yutao Yang , Junsheng Hao , Caixia Yin , Fangjun Huo , Jianbin Chao , Diansheng Liu
      A new compound based on 2-quinolinone derivative with very little side effects on organisms, 3-(1H-benzo[d]imidazol-2-yl)-6,7-difluoroquinolin-2(1H)-one, has been designed, synthesized and characterized. And its recognition ability was firstly studied by spectroscopy. The result indicated that the compound shows high selectivity for Hg2+ over other metal ions with detectable fluorescent signals in aqueous-methanol media. The proposed mechanism is that the fluorescence of the probe was quenched due to the effect from spin–orbit coupling of Hg2+ after the probe coordinated with Hg2+, and was proved by ESI-MS and 1H NMR analysis.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Hidden physics in molecular rovibrational spectrum
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Weiguo Sun , Yi Zhang , Qunchao Fan , Hao Feng , Jia Fu , Huidong Li , Jie Ma , Liantuan Xiao , Suotang Jia
      An algebraic method for rotational energies (AMr) is proposed to unearth the rotational spectrum {ɛJ } and the rovibrational interaction energies ε υ J int that are hidden in the rovibrational energies EυJ . The applications to the excited electronic state a 3 Σ u + of 7 Li 2 and the ground state X 1 Σ + of NaF molecules show that: (1) the rotational energies ɛJ of the lighter 7 Li 2 molecule have better accuracies than the widely used rigid rotor rotational energies ε J rr particularly for the lowest two rotational states, while the rigid rotor model produces satisfied rotational energies for the heavier NaF molecule and (2) the attractive rovibrational interaction energies ε υ J int stabilize a molecular rovibrational system.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Turn-on electrochemiluminescence sensing of Cd2+ based on CdTe quantum
           dots
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Honglei Song , Miao Yang , Xinxin Fan , Haiyan Wang
      A simple and sensitive method for the detection of cadmium ion was proposed based on the electrochemiluminescence (ECL) of thioglycolic acid capped-CdTe quantum dots (CdTe QDs). The ECL of CdTe QDs was firstly quenched by introduction of S2 − and was restored due to following addition of Cd2+, on the basis of which, a “turn-on” ECL method for the detection of Cd2+ was demonstrated. The ECL of CdTe QDs exhibited linear response toward Cd2+ concentration in the range from 6.3nM to 3.4μM (R =0.999) with a detection limit of 2.1nM. The proposed assay was simple, sensitive, selective, and practicable in real water samples.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Comparative study for determination of some polycyclic aromatic
           hydrocarbons ‘PAHs’ by a new spectrophotometric method and
           multivariate calibration coupled with dispersive liquid–liquid
           extraction
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Omar Abdel-Aziz , A.M. El Kosasy , S.M. El-Sayed Okeil
      A modified dispersive liquid–liquid extraction (DLLE) procedure coupled with spectrophotometric techniques was adopted for simultaneous determination of naphthalene, anthracene, benzo(a)pyrene, alpha-naphthol and beta-naphthol in water samples. Two different methods were used, partial least-squares (PLS) method and a new derivative ratio method, namely extended derivative ratio (EDR). A PLS-2 model was established for simultaneous determination of the studied pollutants in methanol, by using twenty mixtures as calibration set and five mixtures as validation set. Also, in methanol a novel (EDR) method was developed for determination of the studied pollutants, where each component in the mixture of the five PAHs was determined by using a mixture of the other four components as divisor. Chemometric and EDR methods could be also adopted for determination of the studied PAH in water samples after transferring them from aqueous medium to the organic one by utilizing dispersive liquid–liquid extraction technique, where different parameters were investigated using a full factorial design. Both methods were compared and the proposed method was validated according to ICH guidelines and successfully applied to determine these PAHs simultaneously in spiked water samples, where satisfactory results were obtained. All the results obtained agreed with those of published methods, where no significant difference was observed.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • A mechanosynthesized, sequential, cyclic fluorescent probe for mercury and
           iodide ions in aqueous solutions
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Shangwen Chen , Pipi Wang , Chunmei Jia , Qiang Lin , Wenbing Yuan
      A fluorescent Hg2+-selective chemosensor, 2,5-dimethoxybenzaldehyde thiosemicarbazone (1), was quantitatively prepared by grinding 2,5-dimethoxybenzaldehyde and thiosemicarbazide together in a ball mill for 15min. The excitation and emission maxima of compound 1 are 347 and 450nm, respectively. The reaction of this ligand with Hg2+ was investigated by FT-IR, 1H NMR, and fluorescence titration. Results show that the composition of the resulting Hg complex 1-Hg is 2:1 1:Hg, and that the S and imino N atoms serve as the binding sites of the ligand to the Hg2+ ions. Coordination-assisted fluorescence quenching results show that compound 1 exhibits a highly selective fluorescence response to trace amounts of Hg2+ in water. More importantly, the resulting complex 1-Hg can be used as a turn-on fluorescence probe for I− at a detection limit of 8.4×10−8 M. Thus, compound 1 is a relatively stable, sequential, cyclic fluorescent probe for Hg2+ and I−.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • DFT simulations and vibrational spectra of
           2-amino-2-methyl-1,3-propanediol
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): T.S. Renuga Devi , J. Sharmi kumar , G.R. Ramkumaar
      The FTIR and FT-Raman spectra of 2-amino-2-methyl-1,3-propanediol were recorded in the regions 4000–400cm−1 and 4000–50cm−1 respectively. The structural and spectroscopic data of the molecule in the ground state were calculated using Hartee-Fock and density functional method (B3LYP) with the augmented-correlation consistent-polarized valence double zeta (aug-cc-pVDZ) basis set. The most stable conformer was optimized and the structural and vibrational parameters were determined based on this. The complete assignments were performed on the basis of the Potential Energy Distribution (PED) of the vibrational modes, calculated using Vibrational Energy Distribution Analysis (VEDA) 4 program. With the observed FTIR and FT-Raman data, a complete vibrational assignment and analysis of the fundamental modes of the compound were carried out. Thermodynamic properties and Mulliken charges were calculated using both Hartee-Fock and density functional method using the aug-cc-pVDZ basis set and compared. The calculated HOMO-LUMO energy gap revealed that charge transfer occurs within the molecule. 1H and 13C NMR chemical shifts of the molecule were calculated using Gauge-Independent Atomic Orbital (GIAO) method and were compared with experimental results.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Spectroscopic characterization of recently excavated archaeological
           potsherds from Tamilnadu, India with multi-analytical approach
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): G. Raja Annamalai , R. Ravisankar , A. Rajalakshmi , A. Chandrasekaran , K. Rajan
      A combined analytical study of potsherds excavated from different archaeological sites of Tamilnadu (Kavalapatti, Nattapuraki and Thamaraikulam villages), India are analyzed by spectroscopic techniques such as FTIR, X-ray diffraction, thermogravimetric analysis (TGA) and Scanning Electron Microscope (SEM) coupled with Energy Dispersive Spectrometer (EDS). FTIR and XRD techniques have been attempted to characterize the mineralogical composition, firing temperature and firing conditions of the archaeological potsherds. Thermogravimetric analysis (TGA) is the complementary study to estimate the firing temperature from characteristic thermal reactions in potsherds under controlled firing in inert gas atmosphere. Further, Scanning Electron Microscopy (SEM) equipped and coupled with an Energy Dispersive Spectrometer (EDS) to analyze internal morphology and chemical composition of the potsherds was used. From the results of the above techniques, the firing temperatures of potsherds were found to be greater than 650°C.
      Graphical abstract image Highlights A typical EDS spectrum of potsherd from Tamilnadu

      PubDate: 2014-06-18T17:25:07Z
       
  • Determination of acetylsalicylic acid in commercial tablets by SERS using
           silver nanoparticle-coated filter paper
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Loriz Francisco Sallum , Frederico Luis Felipe Soares , Jorge Armando Ardila , Renato Lajarim Carneiro
      In this work, filter paper was used as a low cost substrate for silver nanoparticles in order to perform the detection and quantification of acetylsalicylic acid by SERS in a commercial tablet. The reaction conditions were 150mM of ammonium hydroxide, 50mM of silver nitrate, 500mM of glucose, 12min of the reaction time, 45°C temperature, pretreatment with ammonium hydroxide and quantitative filter paper (1–2μm). The average size of silver nanoparticles deposited on the paper substrate was 180nm. Adsorption time of acetylsalicylic acid on the surface of the silver-coated filter paper was studied and an adsorption time of 80min was used to build the analytical curve. It was possible to obtain a calibration curve with good precision with a coefficient of determination of 0.933. The method proposed in this work was capable to quantify acetylsalicylic acid in commercial tablets, at low concentration levels, with relative error of 2.06% compared to the HPLC. The preparation of filter paper coated with silver nanoparticles using Tollen’s reagent presents several advantages such as low cost of synthesis, support and reagents; minimum amount of residuals, which are easily treated, despite the SERS spectroscopy presenting fast analysis, with low sample preparation and low amount of reactants as in HPLC analysis.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Kamlet–Taft and Catalán solvatochromism of some π-expanded
           phenanthrimidazole derivatives – DFT analysis
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): J. Jayabharathi , P. Ramanathan , V. Thanikachalam , A. Arunpandiyan
      Some π-expanded phenanthrimidazole derivatives have been synthesised and characterised by different spectral techniques. Kamlet–Taft and Catalán solvatochromism of synthesised phenanthrimidazole derivatives have been analysed. Non-linear optical (NLO) and natural bond orbital (NBO) analysis have been made by ab initio method to show intramolecular interactions. The energies of the HOMO and LUMO levels, the molecular electrostatic potential (MEP) energy surface, NBO studies have exploited the existence of intramolecular charge transfer (ICT) within the molecule.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • ATR-FTIR spectroscopy and quantitative multivariate analysis of paints and
           coating materials
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Philippa Alice Hayes , Signe Vahur , Ivo Leito
      The applicability of ATR-FTIR spectroscopy with partial least squares (PLS) data analysis was evaluated for quantifying the components of mixtures of paint binding media and pigments, and alkyd resins. PLS methods were created using a number of standard mixtures. Validation and measurement uncertainty estimation was carried out. Binary, ternary and quaternary mixtures of several common binding media and pigments were quantified, with standard measurement uncertainties in most cases below 3g/100g. Classes of components – aromatic anhydrides and alcohols – used in alkyd resin synthesis were also successfully quantified, with standard uncertainties in the range of 2–3g/100g. This is a more demanding application because in alkyd resins aromatic anhydrides and alcohols have reacted to form a polyester, and are not present in their original forms. Once a PLS method has been calibrated, analysis time and cost are significantly reduced from typical quantitative methods such as GC/MS. This is beneficial in the case of routine analysis where the components are known.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Biosynthesis of gold nanoparticles using Sargassum swartzii and its
           cytotoxicity effect on HeLa cells
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): T. Stalin Dhas , V. Ganesh Kumar , V. Karthick , K. Govindaraju , T. Shankara Narayana
      In this investigation, biological synthesis of gold nanoparticles (AuNPs) using Sargassum swartzii and its cytotoxicity against human cervical carcinoma (HeLa) cells is reported. The biological synthesis involved the reduction of chloroauric acid led to the formation of AuNPs within 5min at 60°C and the formation of AuNPs was confirmed using UV–vis spectrophotometer. The AuNPs were stable; spherical in shape with well-defined dimensions, and the average size of the particle is 35nm. A zeta potential value of −27.6mV revealed synthesized AuNPs were highly stable. The synthesized AuNPs exhibited a dose-dependent cytotoxicity against human cervical carcinoma (HeLa) cells. Furthermore, induction of apoptosis was measured by DAPI (4′,6-Diamidino-2-phenylindole dihydrochloride) staining.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • A combined experimental and theoretical investigation of a new imineoxime
           and its palladium(II) and platinum(II) complexes: Synthesis, structural
           characterization and spectroscopic properties
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Yunus Kaya , Ceyda Icsel , Veysel T. Yilmaz , Orhan Buyukgungor
      A new imineoxime compound {(1E,2E)-(2-hydroxy-ethylimino)-naphthalene-2yl-ethanal oxime (heineoH)} and its palladium(II) and platinum(II) complexes ([M(heineo)2]) have been synthesized and characterized by IR, NMR, UV–vis, elemental analysis, mass spectra and X-ray single crystal diffraction. [Pt(heineo)2] was obtained as a single crystal, while [Pd(heineo)2] was synthesized as a polycrystalline powder. The X-ray diffraction analysis of the [Pt(heineo)2] indicated that the platinum(II) ion is coordinated by two heineo ligands in a distorted square-planar geometry. DFT (B3LYP/6-311++G(d,p) and LANL2DZ) calculations on the ligand and its complexes were carried out to correlate the geometry and vibrational and electronic properties. Additionally, heineoH is fluorescent in EtOH at room temperature, but the fluorescence is quenched in the case of the metal complexes.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Application of response surface methodology for determination of methyl
           red in water samples by spectrophotometry method
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Saeid Khodadoust , Mehrorang Ghaedi
      In this study a rapid and effective method (dispersive liquid–liquid microextraction (DLLME)) was developed for extraction of methyl red (MR) prior to its determination by UV–Vis spectrophotometry. Influence variables on DLLME such as volume of chloroform (as extractant solvent) and methanol (as dispersive solvent), pH and ionic strength and extraction time were investigated. Then significant variables were optimized by using a Box–Behnken design (BBD) and desirability function (DF). The optimized conditions (100μL of chloroform, 1.3mL of ethanol, pH 4 and 4% (w/v) NaCl) resulted in a linear calibration graph in the range of 0.015–10.0mgmL−1 of MR in initial solution with R 2 =0.995 (n =5). The limits of detection (LOD) and limit of quantification (LOQ) were 0.005 and 0.015mgmL−1, respectively. Finally, the DLLME method was applied for determination of MR in different water samples with relative standard deviation (RSD) less than 5% (n =5).
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Photoinduced interaction studies on
           N-(2-methylthiophenyl)-2-hydroxy-1-naphthadiamine with TiO2 nanoparticles:
           A combined experimental and theoretical (DFT and spectroscopic) approach
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): S. Pushpam , S. Gayathri , V. Ramakrishnan
      Schiff base derivative synthesized by the reaction of 2-(methylthio) aniline and 2-hydroxy-1-naphthaldehyde exhibits keto-amine tautomerism in methanol solvent. The fluorescence quenching of N-(2-methyl thiophenyl)-2-hydroxy-1-naphthadiamine (NMTHN) by TiO2 nanoparticles in methanol has been studied. The excitation and emission peaks have been observed at 439 and 509nm respectively. The apparent association constant has been deduced from the absorption spectral changes of NMTHN–TiO2 nanoparticles using Bensi-Hildebrand equation. The number of binding sites and the binding constant have been calculated from the relevant fluorescence data. Quenching of fluorescence of NMTHN by TiO2 could be due to a dynamic mode. Density Functional Theory (DFT) calculations also have been performed to study the charge distribution of NMTHN–TiO2 both in ground and excited states. The HOMO–LUMO analysis of NMTHN–TiO2 in the ground state has been made.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Vibrational spectra (FT-IR and FT-Raman), molecular structure, natural
           bond orbital, and TD-DFT analysis of l-Asparagine Monohydrate by Density
           Functional Theory approach
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): S. Sylvestre , S. Sebastian , S. Edwin , M. Amalanathan , S. Ayyapan , T. Jayavarthanan , K. Oudayakumar , S. Solomon
      In this work we report the vibrational spectral analysis of l-Asparagine Monohydrate (LAM) molecule by using FT-IR and FT-Raman spectroscopic techniques. The equilibrium geometry, harmonic vibrational wavenumbers, various bonding features have been computed using density functional B3LYP method with 6-311G(d,p) as basis set. Stability of the molecule arising from hyperconjugative interactions, charge delocalization have been analyzed using natural bond orbital (NBO) analysis. The results show that charge in electron density (ED) in σ* and π* antibonding orbitals and second order delocalization energies E (2) confirms the occurrence of Intramolecular Charge Transfer (ICT) within the molecule. The energy and oscillator strength calculated by Time-Dependent Density Functional Theory (TD-DFT) complements with the experimental findings. The simulated spectra satisfactorily coincide with the experimental spectra.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis and spectral characterization of new homologous
           1,3,5-triaryl-2-pyrazolines: Influence of alkyloxy chain length on
           fluorescence
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Asghar Abbas , Safdar Hussain , Noureen Hafeez , Muhammad Moazzam Naseer
      Twelve new homologous 1,3,5-triaryl-2-pyrazolines (1c–12c) have been synthesized and characterized on the basis of their spectral (IR, 1H and 13C NMR and MS) data and microanalysis. The influence of alkyloxy chain length on absorption and fluorescence properties of 1c–12c was studied by UV–Vis and emission spectroscopy. For all the compounds, fluorescence was observed in the blue region of the visible spectrum. Furthermore, a strong influence of alkyloxy chain length was found on the emission intensity of 1,3,5-triaryl-2-pyrazolines, without causing any major blue- or red-shift in the emission wavelength (λ max em). The absorption and emission maxima (λ max abs and λ max em) for all the compounds were observed in the range of 408–416nm and 471–476nm, respectively. The effect of chloro-substituent present on the conjugated backbone of 1,3,5-triaryl-2-pyrazoline moiety is also discussed.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Biogenic copper oxide nanoparticles synthesis using Tabernaemontana
           divaricate leaf extract and its antibacterial activity against urinary
           tract pathogen
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Rajeshwari Sivaraj , Pattanathu K.S.M. Rahman , P. Rajiv , Hasna Abdul Salam , R. Venckatesh
      This investigation explains the biosynthesis and characterization of copper oxide nanoparticles from an Indian medicinal plant by an eco-friendly method. The main objective of this study is to synthesize copper oxide nanoparticles from Tabernaemontana divaricate leaves through a green chemistry approach. Highly stable, spherical copper oxide nanoparticles were synthesized by using 50% concentration of Tabernaemontana leaf extract. Formation of copper oxide nanoparticles have been characterized by UV–Vis absorption spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX) and transmission electron microscopy (TEM) analysis. All the analyses revealed that copper oxide nanoparticles were 48±4nm in size. Functional groups and chemical composition of copper oxide were also confirmed. Antimicrobial activity of biogenic copper oxide nanoparticles were investigated and maximum zone of inhibition was found in 50μg/ml copper oxide nanoparticles against urinary tract pathogen (Escherichia coli).
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • FT-IR, FT-Raman and UV spectroscopic investigation, electronic properties,
           electric moments, and NBO analysis of anethole using quantum chemical
           calculations
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): L. Sinha , O. Prasad , S. Chand , A.K. Sachan , S.K. Pathak , V.K. Shukla , M. Karabacak , A.M. Asiri
      FT-IR and FT-Raman spectra of anethole (1-Methoxy-4-(1-propenyl)benzene), a flavoring agent of commercial value, have been recorded in the regions 4000–400 and 4000–100cm−1 respectively. The structure of the title molecule has been optimized and the structural parameters have been calculated by DFT/B3LYP method with 6-311++G(d,p) basis set. The fundamental vibrational wavenumbers as well as their intensities were calculated and a good agreement between observed and scaled calculated wavenumbers has been achieved. UV–Vis spectrum of the title compound was recorded in the region 200–500nm and the electronic properties such as HOMO and LUMO energies and associated energy gap were calculated by Time dependent-density functional theory (TD-DFT) approach. Nonlinear optical (NLO) study divulges the nonlinear properties of the molecule. Stability of the title molecule arising from hyper-conjugative interactions and charge delocalization has been investigated using natural bond orbital (NBO) analysis. The theoretical results were found to be in coherence with the measured experimental data.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Detection of perchlorate using Ag/DMAH+ SERS-active capture matrices
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): P.A. Mosier-Boss , M.D. Putnam
      In this communication, the fabrication of SERS-active capture matrices for the detection of perchlorate is described. The amine groups of amine-modified magnetic microparticles were used to immobilize silver colloidal particles. Once immobilized, the silver was reacted with dimethylaminoethanethiol hydrochloride (DMAH+Cl−) to form a self-assembled monolayer (SAM). The DMAH+ SAM exhibits reasonably good selectivity for perchlorate. It was shown that calibration curves could be generated by ratioing the perchlorate peak with a DMAH+ peak that did not change upon interaction with the perchlorate ion. Flow experiments, using Ag/DMAH+ capture matrices held in place by a magnet, showed instantaneous response to changes in perchlorate concentration. The use of solid phase extraction (SPE) to eliminate chloride ion interference was explored.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis and characterization of metal complexes of Schiff base ligand
           derived from imidazole-2-carboxaldehyde and 4-aminoantipyrine
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): R. Selwin Joseyphus , C. Shiju , J. Joseph , C. Justin Dhanaraj , D. Arish
      The Co(II), Ni(II), Cu(II) and Zn(II) complexes of the Schiff base derived from imidazole-2-carboxaldehyde and 4-aminoantipyrine were synthesized. These compounds were characterized by elemental analysis, IR, mass, 1H NMR, electronic spectra, magnetic moment, molar conductance, thermal analysis, powder XRD and SEM. The analytical data show that the metal to ligand ratio is 1:1. The IR results show that the ligand acts as a bidentate donor coordinating through the azomethine nitrogen and imidazole nitrogen atoms. From the electronic spectra and magnetic moment value predicts the geometry of the complexes. The surface morphology of the compounds was studied by SEM. The compounds were screened for their antibacterial activity and antifungal activity using Kirby Bayer disc diffusion method. The DNA cleavage and superoxide dismutase activities of the compounds were investigated. The anticancer activities of the complexes have been carried out towards HeLa and HCT116 cancer cells.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • N-phenyl-1-naphthylamine/β-cyclodextrin inclusion complex as a new
           fluorescent probe for rapid and visual detection of Pd2+
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Munisamy Maniyazagan , Sonaimuthu Mohandoss , Krishnamoorthy Sivakumar , Thambusamy Stalin
      Inclusion complex between N-phenyl-1-naphthylamine (NPN) and β-cyclodextrin (β-CD) was studied by FT-IR, 1H and 2D NMR, XRD, FT-Raman, SEM and DSC techniques. The formation of 1:1 stoichiometric inclusion complex of NPN with β-CD was proposed based on the Nuclear magnetic resonance spectroscopy and Molecular docking study. The molecular encapsulation of host–guest inclusion complex based on simple chemosensor has high selectivity and sensitivity for the determination of Pd2+ ion. Host–guest inclusion complex as a spectroscopic probe is used for the detection of transition metal cation Pd2+. Coordination of this Pd2+ with (NPN/β-CD) inclusion complex exhibited a noticeable color change in the solution state it used for naked-eye detection.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Self-assembly of Terbium(III)-based metal–organic complexes with
           two-photon absorbing active
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Dandan Li , Nanqi Shao , Xianshun Sun , Guocui Zhang , Shengli Li , Hongping Zhou , Jieying Wu , Yupeng Tian
      Hybrid complexes based on D-π-A type dyes p-aminostyryl-pyridinum and Terbium(III) complex anion (1, 2) have been synthesized by ionic exchange reaction. Meanwhile two different alkyl-substituted amino groups were used as electron donors in organic dyes cations. The synthesized complexes were characterized by element analysis. In addition, the structural features of them were systematic studied by single crystal X-ray diffraction analysis. Their linear properties have been systematically investigated by absorption spectra and fluorescence, the results show that the energy transfer takes place from the trans-4-[4′-(N,N-diethylamino)styryl]-N-methyl pyridinium (2 ′) cation to Tb(III). In addition, complex 2 exhibit a large two-photon absorption coefficient β: 0.044cm/GW at 710nm.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis, characterization and spectroscopic behavior of novel
           2-oxo-1,4-disubstituted-1,2,5,6-tetrahydrobenzo[h]quinoline-3-carbonitrile
           dyes
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Salman A. Khan , Abdullah M. Asiri , Saad H. Al-Thaqafy , Hassan M. Faidallah , Samy A. El-Daly
      Two synthetic pathways were adopted to synthesize the target 2-oxo-1,4-disubstituted-1,2,5,6-tetrahydro-benzo[h]quinoline-3-carbonitriles. Structure of the synthesized compounds has been characterized based on FT-IR, 1H NMR, 13C NMR and elemental analyses. UV–Vis and fluorescence spectroscopy measurements provided that all compounds are good absorbent and fluorescent. Fluorescence polarity study demonstrated that these compounds were sensitive to the polarity of the microenvironment provided by different solvents. In addition, spectroscopic and physicochemical parameters, including singlet absorption, extinction coefficient, Stokes shift, oscillator strength and dipole moment were investigated in order to explore the analytical potential of synthesized compounds.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Quantum dots (QDs) based fluorescence probe for the sensitive
           determination of kaempferol
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Xuanping Tan , Shaopu Liu , Yizhong Shen , Youqiu He , Jidong Yang
      In this work, using the quenching of fluorescence of thioglycollic acid (TGA)-capped CdTe quantum dots (QDs), a novel method for the determination of kaempferol (KAE) has been developed. Under optimum conditions, a linear calibration plot of the quenched fluorescence intensity at 552nm against the concentration of KAE was observed in the range of 4–44μgmL−1 with a detection limit (3σ/K) of 0.79μgmL−1. In addition, the detailed reaction mechanism has also been proposed on the basis of electron transfer supported by ultraviolet–visible (UV–vis) absorption and fluorescence (FL) spectroscopy. The method has been applied for the determination of KAE in pharmaceutical preparations with satisfactory results. The proposed method manifested several advantages such as high sensitivity, short analysis time, low cost and ease of operation.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Vibrational spectroscopy of the sulphate mineral sturmanite from Kuruman
           manganese deposits, South Africa
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Ray L. Frost , Ricardo Scholz , Andrés López , Yunfei Xi , Cristiano Lana
      The mineral sturmanite is a hydrated calcium iron aluminium manganese sulphate tetrahydroxoborate hydroxide of formula Ca6(Fe, Al, Mn)2(SO4)2(B(OH)4)(OH)12·26H2O. We have studied the mineral sturmanite using a number of techniques, including SEM with EPMA and vibrational spectroscopy. Chemical analysis shows a homogeneous phase, composed by Ca, Fe, Mn, S, Al and Si. B is not determined in this EPMA technique. An intense Raman band at 990cm−1 is assigned to the SO4 2− symmetric stretching mode. Raman spectroscopy identifies multiple sulphate symmetric stretching modes in line with the three sulphate crystallographically different sites. Raman spectroscopy also identifies a band at 1069cm−1 which may be attributed to a carbonate symmetric stretching mode, indicating the presence of thaumasite. Infrared spectra display two bands at 1080 and 1107cm−1 assigned to the SO4 2− antisymmetric stretching modes. The observation of multiple bands in this ν 4 spectral region offers evidence for the reduction in symmetry of the sulphate anion from T d to C 2v or even lower symmetry. The Raman band at 3622cm−1 is assigned to the OH unit stretching vibration and the broad feature at around 3479cm−1 to water stretching bands. Infrared spectroscopy shows a set of broad overlapping bands in the OH stretching region. Vibrational spectroscopy enables an assessment of the molecular structure of sturmanite to be made.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis, characterization and dielectric properties of SnO2 thin films
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): M. Ali Yıldırım , Sümeyra Tuna Yıldırım , Emine Fedakar Sakar , Aytunç Ateş
      SnO2 thin films have been grown on glass substrates using Successive Ionic Layer Adsorption and Reaction (SILAR) method at room temperature and ambient pressure. The annealing temperature effect on the structural, morphological, optical and electrical properties of SnO2 thin films has been investigated. The X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) studies have showed that all the films have exhibited polycrystalline nature with tetragonal structure and have been covered well on glass substrates. The crystalline and surface properties of the films have improved with increasing annealing temperature. The band gap values have been changed from 3.73 to 3.66eV depending on the annealing temperature. The refractive index (n), optical static and high frequency dielectric constants (ε o, ε ∞) values have been calculated as a function of the annealing temperature. The resistivity values of the films have changed between 10−1 – 10−3 Ωcm with annealing temperature and light at room temperature.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • A selectively fluorescein-based colorimetric probe for detecting
           copper(II) ion
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Li Zhang , Xianhong Zhang
      A novel fluorescein derivative 3-bromo-5-methylsalicylaldehyde fluorescein hydrazone (BMSFH) has been synthesized by reacting fluorescein hydrazide with 3-bromo-5-methylsalicylaldehyde and was developed as a new colorimetric probe for detection of Cu2+. In the presence of Cu2+ the BMSFH exhibits a rapid color change from colorless to yellow together with an obvious new band appeared at 502nm in the UV–vis absorption spectra. However, other common alkali-, alkaline earth-, transition- and rare earth metal ions induced no or minimal spectral changes. This change is attributed to BMSFH via coordination with Cu2+ in a 1:1 stoichiometry and this binding to Cu2+ is reversible, as indicated by the bleaching of the color when the Cu2+ is extracted with EDTA. Experimental results indicate that the BMSFH can provide a rapid, selective and sensitive response to Cu2+ with a linear dynamic range 3.0–330μmol/L and can be used as a potential Cu2+ colorimetric probe in aqueous solution.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • ESIPT inspired dual fluorescent probe (Z)-3-((4-(4-aminobenzyl) phenyl)
           amino)-1,3-diphenylprop-2-en-1-one: Experimental and DFT based approach to
           photophysical properties
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): V. Latha , B. Annaraj , M.A. Neelakantan
      A fluorescent probe (Z)-3-((4-(4-aminobenzyl) phenyl) amino)-1,3-diphenylprop-2-en-1-one (L) was synthesized and characterized by IR, 1H NMR, ESI mass, UV–visible and fluorescence spectroscopy and by single crystal X-ray diffraction. The molecule has a stable helical structure due to intermolecular CH π interaction. The thermal stability of L was studied by TG analysis. The electronic structure calculations of L have been carried out using DFT at B3LYP/6-31G (d,p) level. The vibrational frequencies and 1H NMR spectra were computed at this level and compared with experimental values. Major orbital contributions for the electronic transitions were assigned with the help of time-dependent density functional theory (TD-DFT). The observed electronic absorption spectra of L in different solvents coincide with the computed spectra in keto form. The dual emission and high Stokes shift values support the excited state intramolecular proton transfer (ESIPT) process. The molecular docking has been employed to get information about the interaction of L with DNA [6BNA].
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Fluorescent sensor for selective detection of Al3+ based on
           quinoline–coumarin conjugate
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Jing-can Qin , Tian-rong Li , Bao-dui Wang , Zheng-yin Yang , Long Fan
      A fluorescence probe, 8-formyl-7-hydroxyl-4-methyl coumarin – (2′-methylquinoline-4-formyl) hydrazone (L) has been synthesized. The chemosensor is found preferential binding to Al3+ in presence of other competitive ions with associated changes in its optical and fluorescence spectra behavior. Upon addition of Al3+ to a solution of L, it shows 200-fold enhancement of fluorescence intensity which might be attributed to form a 2:1 stoichiometry of the binding mode of L Al(III) and the chelation enhanced fluorescence (CHEF) process at 479nm in ethanol. The lowest detection limit for Al3+ is determined as 8.2×10−7 M.
      Graphical abstract image

      PubDate: 2014-06-18T17:25:07Z
       
  • Impedance spectroscopic characterization of Sm2O3 containing lithium
           borate glasses
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): D.D. Ramteke , R.S. Gedam
      27.5 Li2O–(72.5–X) B2O3–X Sm2O3 (X =0.5, 1, 1.5 and 2) were prepared by conventional melt quench technique. Impedance spectroscopy (IS) is used to study the electrical properties of these prepared glasses. Modulus formalism is introduced to study relaxation behaviour of these glasses. Scaling model shows the good overlap of data on single master curve which suggests that conduction mechanism in these glasses is compositional dependent. Variation of dielectric constant and dielectric loss with the addition of Sm2O3 and frequency are discussed here.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Fabrication and characterization of ZnO@CdS core–shell nanostructure
           using acetate precursors: XRD, FESEM, DRS, FTIR studies and effects of
           cadmium ion concentration on band gap
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Mohammad Hossein Habibi , Mohammad Hossein Rahmati
      ZnO@CdS core–shell nano-structure has been synthesized using zinc acetate dihydrate, and cadmium acetate dihydrate as simple precursors in a water–ethanol matrix without using any surfactant, ligand or chelating agents. The effect of different concentrations of cadmium acetate and sodium sulfide on optical and electronic properties of ZnO@CdS core–shell was investigated. The morphology and structure of the ZnO@CdS core–shell nano-structures have been confirmed by field-emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) measurements. The results showed that the ZnO@CdS core–shell nano-structure is mixed cubic and hexagonal structures. FESEM results showed the mono-dispersed and uniform size of 39nm. Optical properties were studied by UV–visible diffuse reflectance spectroscopy (DRS) technique and the results showed that band gaps of ZnO@CdS core–shell nanocomposites were red shifted by increasing the cadmium concentration. FTIR spectrum of ZnO@CdS core–shell nano-structure showed a band at 482cm−1 correlated to ZnO bond and a band at 630cm−1 due to the stretching frequency of CdS bond.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • New fluorescent symmetrically substituted
           perylene-3,4,9,10-dianhydride-azohybrid dyes: Synthesis and spectroscopic
           studies
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): Aamer Saeed , Ghulam Shabir
      Five phenolic azo-dyes (3a–e) were synthesized by diazo coupling of the suitably substituted anilines (1a–e) with phenol at low temperature in alkaline medium. The resulting dyes have low solubility in aqueous medium due to lack of carboxylic or sulfonic solubilizing functionalities. The hybridization of perylene dianhydride with phenolic azo-dyes was achieved by the nucleophilic aromatic substitution (SNAr) reaction of perylene-3,4,9,10-dianhydride 4 with phenolic azo-dyes 3a–e in basic medium. The hybrid dyes exhibit absorption maxima λ max in the range 440–460nm in aqueous medium due to presence of azo linkage and highly conjugated system of π bonds. Fluorescence spectra of these dyes in water show sharp emission peaks with small band widths. The structures of perylene-azo dyes were confirmed by FTIR and NMR spectroscopy.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Synthesis, structural analysis, theoretical studies of some lawsone
           derivatives
    • Abstract: Publication date: 10 December 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 133
      Author(s): S. Elavarasan , M. Gopalakrishnan
      A series of lawsone derivatives are synthesized. The structures of the synthesized compounds are analyzed by FT-IR, Mass, Elemental analysis, 1H, 13C, HSQC, HMBC and theoretical studies.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Palladium(II) and zinc(II) complexes of neutral [N2O2] donor Schiff bases
           derived from furfuraldehyde: Synthesis, characterization, fluorescence and
           corrosion inhibitors of ligands
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Omyma A.M. Ali
      Metal complexes of Schiff bases derived from furfuraldehyde and 4,5-dimethyl-1,2-phenylendiamine (L1) or 4,5-dichloro-1,2-phenylendiamine (L2) have been reported and characterized based on elemental analyses, IR, 1H NMR, UV–Vis, magnetic moment, molar conductance and thermal analysis. The complexes are found to have the formulae [PdL1–2]Cl2 and [ZnL1–2](AcO)2·H2O. The molar conductance data reveal that Pd(II) and Zn(II) chelates are ionic in nature and are of the type 2:1 electrolytes. The spectral data are consistent with a square planar and tetrahedral geometry around Pd(II) and Zn(II), respectively, in which the ligands act as tetradentate ligands. The thermal behavior of some chelates is studied and the activation thermodynamic parameters are calculated using Coats–Redfern method. The corrosion inhibition of stainless steel types 410 and 304 in 1M HCl using the synthesized Schiff bases as inhibitors have been studied by weight loss method. The obtained data considered these ligands as efficient corrosion inhibitors. The ligands and their metal complexes exhibited considerable antibacterial activity against Staphylococcus aureus, and Escherichia coli and antifungal activity against Candida albicans.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Photophysical insights on effect of gold nanoparticles over
           fullerene–porphyrin interaction in solution
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Ratul Mitra , Ajoy K. Bauri , Shrabanti Banerjee , Sumanta Bhattacharya
      The present article reports the role of gold nanoparticles, i.e., AuNp (having diameter ∼2–4nm), in non-covalent interaction between fullerenes (C60 and C70) and a monoporphyrin (1) in toluene. Both UV–vis and fluorescence measurements reveal considerable reduction in the average value of binding constant (K av) for the C70–1 system (K C70– 1 (av) =19,300dm3 mol−1) in presence of AuNp, i.e., K C70– 1 –AuNp(av) =13,515dm3 mol−1 although no such phenomenon is observed in case of C60–1 system, viz., K C60– 1 (av) =1445dm3 mol−1 and K C60– 1 –AuNp(av) =1210dm3 mol−1. DLS study reveals sizeable amount of increase in the particle size of C70–1–AuNp nanocomposite, i.e., ∼105nm, compared to C60–1–AgNp system, e.g., ∼5.5nm which gives very good support in favor of decrease in the value of K av for the former system. SEM study reveals that nanoparticles are dispersed in larger extent in case of C70–1–AuNp system. Time-resolved fluorescence study envisages that deactivation of the excited singlet state of 1 by C70 takes place at a faster rate in comparison to C60 in presence of gold nanoparticles.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Conformational and vibrational analysis of 18-crown-6–alkali metal
           cation complexes
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): A.A. Al-Kahtani , N.A. Al-Jallal , A.A. El-Azhary
      Conformational analysis was performed for the 18-crown-6–alkali metal cation complexes, 18c6–AMCCs, using the CONFLEX method. The number of predicted conformations of the 18c6–Li+, Na+, K+, Rb+ and Cs+ complexes was 10, 24, 15, 9 and 4 conformations, respectively. Electronic and geometrical structures were calculated for the predicted conformations at the HF, B3LYP, CAM-B3LYP, M06 and MP2 levels. Binding energies and enthalpies of the ground state conformations were also calculated. Vibrational, IR and Raman, spectra of free 18c6 and 18c6–AMCCs were measured. Comparison between the calculated vibrational frequencies using multi-scale-factor scaling of the B3LYP force field and the experimental vibrational frequencies predicted that the 18c6–K+, Rb+ and Cs+ complexes exist in the D 3 d , C 3 v and C 3 v conformations, respectively. It was also predicted that the 18c6–Na+ complex exists in a D 3 d -like conformation. It was not possible to identify in what conformation the 18c6–Li+ complex exists.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Ru-indoloquinoline complex as a selective and effective human telomeric
           G-quadruplex binder
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Hui-juan Yu , Ying Zhao , Wei-jie Mo , Zhi-feng Hao , Lin Yu
      Indoloquinoline and its derivatives have been reported to be a kind of efficient G-quadruplex binder and have been found to interact preferentially to intramolecular G-quadruplex and inhibit telomerase activity in human K562 cells and SW620 cells. In contrast to indoloquinoline derivatives, much less is known about the metal complex based on indoloquinoline or its derivative. In this report, we studied the interaction of ruthenium complex [Ru(bpy)2(itatp)]2+ containing indoloquinoline moiety with human telomeric G-quadruplex DNA (Telo22) and c-myc G-quadruplex DNA (Pu27) by UV–visible (UV–Vis), fluorescence spectroscopy, fluorescent intercalator displacement (FID), thermal denaturation studies and CD spectroscopy. The results suggest that [Ru(bpy)2(itatp)]2+ displays a strong π–π stacking interaction with human telomeric G-quadruplex with a high binding constant (∼107 M−1), but just exhibits moderate binding affinity to c-myc G-quadruplex, thus showing significant selectivity to human telomeric G-quadruplex. The CD titration results indicate that [Ru(bpy)2(itatp)]2+ could effectively convert Telo22 into antiparallel G-quadruplex conformation, while in the c-myc G-quadruplex case, instead of promoting Pu27 to fold into G-quadruplex, [Ru(bpy)2(itatp)]2+ destroys the parallel G-quadruplex structure of Pu27.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
  • Spectroscopic and biological studies of new binuclear metal complexes of a
           tridentate ONS hydrazone ligand derived from
           4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one and
           4,6-diacetylresorcinol
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): Omima M.I. Adly , Adel A.A. Emara
      The binuclear hydrazone, H2L, ligand derived from 4-amino-6-methyl-3-thioxo-3,4-dihydro-1,2,4-triazin-5(2H)-one and 4,6-diacetylresorcinol, in the molar ratio 2:1, and its copper(II), nickel(II), cobalt(II), zinc(II), cadmium(II), cerium(III), iron(III), oxovanadium(IV) and dioxouranium(VI) complexes have been synthesized. Structures of the ligand and its metal complexes were characterized by elemental analyses, spectral (infrared, electronic, mass, 1H NMR and ESR) data, magnetic susceptibility, molar conductivity measurements and thermal gravimetric analysis (TGA). The ligand acts as dibasic with two ONS tridentate sites. The bonding sites are the azomethine nitrogen, phenolate oxygen and sulfur atoms. The metal complexes exhibit different geometrical arrangements such as square planer, tetrahedral and octahedral. The Coats–Redfern equation was used to calculate the kinetic and thermodynamic parameters for the different thermal decomposition steps of some complexes. The ligand and its metal complexes showed antimicrobial activity towards Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Salmonella typhimurium and Escherichia coli), yeast (Candida albicans) and fungus (Aspergillus fumigatus). Structural parameters of the ligand and its metal complexes were theoretically computed on the basis of semiempirical PM3 level, and the results were correlated with their experimental data.
      Graphical abstract image Highlights H2L ligand.

      PubDate: 2014-06-18T17:25:07Z
       
  • Molecular modeling, spectroscopic signature and NBO analysis of some
           building blocks of organic conductors
    • Abstract: Publication date: 11 November 2014
      Source:Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, Volume 132
      Author(s): V. Mukherjee
      Vibrational spectra with IR and Raman intensities in optimum state have been calculated for 2,2′-Bi-1,3-diselenole (commonly known as tetraselenafulvalene) and its halogen derivatives. All these calculations have been done by employing density functional theory (DFT) and second order Moller–Plesset perturbation theory (MP2) methods incorporated with suitable functionals and basis sets. Normal coordinate analysis has also been performed to calculate potential energy distributions (PEDs) to make a conspicuous assignment. The vibrational frequencies of all the four molecules have been assigned using PEDs and the results are compared with available values for the most similar molecules like tetrathiafulvalene. The molecular stability and bond strength have investigated by applying the Natural Bond Orbital (NBO) analysis. The energy gap between HOMO and LUMO is 2.041eV for tetraselenafulvalene and it is slightly less than 2eV for halogen derivatives which implies that these molecules fall in the wide band gap semiconductor groups.
      Graphical abstract image Highlights

      PubDate: 2014-06-18T17:25:07Z
       
 
 
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