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Applied Organometallic Chemistry
[SJR: 0.632] [H-I: 58] [7 followers] Follow

Hybrid journal (It can contain Open Access articles)
ISSN (Print) 0268-2605 - ISSN (Online) 1099-0739
Published by John Wiley and Sons

[1579 journals]

Highly efficient Pd-PEPPSI-IPr catalyst for N-(4-pyridazinyl)-bridged
bicyclic sulfonamides via Suzuki–Miyaura coupling reaction
- Authors: Mallikarhuna Reddy Sura; N. Reddy Bijivemula, Sreekanth Reddy Pogula, Venkata Krishna Reddy Motakatla, Pathak Madhvesh, Vasu Govardhana Reddy Peddiahgari
  Abstract: A protocol for the Suzuki–Miyaura coupling of novel 2-(6-chloropyridazin-3-yl)-5-(aryl/heteroarylsulfonyl)-2,5-diazabicyclo[2.2.1]heptanes and heteroarylboronic acids to afford variety of coupled products was realized. Pd-PEPPSI-IPr catalyst was found to be a powerful and reusable catalyst under relatively mild reaction conditions.A protocol for the Suzuki–Miyaura coupling of novel 2-(6-chloropyridazin-3-yl)-5-(aryl/heteroarylsulfonyl)-2,5-diazabicyclo[2.2.1]heptanes and heteroarylboronic acids to afford variety of coupled products was realized. Pd-PEPPSI-IPr catalyst was found to be a powerful and reusable catalyst under relatively mild reaction conditions.
  PubDate: 2017-10-20T06:32:41.185255-05:
  DOI: 10.1002/aoc.4068
Chemically functionalized silica nanoparticles-based solid-phase
extraction for effective pre-concentration of highly toxic metal ions from
food and water samples
- Authors: Maryam Rajabi; Mohtarameh Rahimi, Maryam Hemmati, Farhood Najafi
  Abstract: In this research study, an efficient solid-phase extraction procedure based on a new organometallic, effective, eco-friendly and bio-degradable nanoadsorbent was firstly introduced for influential pre-concentration of Cu(II), Zn(II), Pb(II), Cd(II) and Mn(II) ions from food and water samples followed by flame atomic absorption spectrophotometric determination. This safe adsorbent consisted of silica nanoparticles chemically functionalized with di-ethylen tri-amine (SiO2@NH2NPs); easily prepared via an effective and simple approach. Characterization of SiO2@NH2NPs was subsequently implemented via SEM, FT-IR and XRD; certifying high quality of the modified nanoadsorbent in terms of size, shape and surface functional groups. The effects of the main factors on the extraction efficiency were then optimized. Efficient extraction of the analytes of interest at neutral media accompanied with the aid of a bio-compatible organometallic nanoadsorbent can be considered as valuable advantages of the proposed approach. In the optimum conditions, calibration graphs were linear in the range of 4–700 μg l−1, with higher correlation coefficients than 0.997 and limits of detection of 1.45–4.10 ng ml−1. The enrichment factor values were found to be in the span of 120–400. The resultant extraction recovery values were satisfactory; possessing the proper relative standard deviation (%, n = 5) values of 2.05–4.28%.In this research study, an efficient solid-phase extraction procedure based on a new organometallic, effective, eco-friendly and bio-degradable nanoadsorbent was firstly introduced for influential pre-concentration of Cu(II), Zn(II), Pb(II), Cd(II) and Mn(II) ions from food and water samples followed by flame atomic absorption spectrophotometric determination. This safe adsorbent consisted of silica nanoparticles chemically functionalized with di-ethylen tri-amine (SiO2@NH2NPs); easily prepared via an effective and simple approach.
  PubDate: 2017-10-19T03:41:01.919363-05:
  DOI: 10.1002/aoc.4012
Nanomagnetically modified vitamin B3 (Fe3O4@Niacin): An efficient and
reusable green biocatalyst for microwave-assisted rapid synthesis of
2-amino-3-cyanopyridines in aqueous medium
- Authors: Mojgan Afradi; Sjjad Abbasi Pour, Maryam Dolat, Afshin Yazdani-Elah-Abadi
  Abstract: Superparamagnetic nanoparticles of modified vitamin B3 (Fe3O4@Niacin) represent a new, efficient and green biocatalyst for the one-pot synthesis of 2-amino-3-cyanopyridine derivatives via four-component condensation reaction between aldehydes, ketones, malononitrile, and ammonium acetate under microwave irradiation in water. This new magnetic organocatalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least six times without significant degradation in the activity. The catalyst was fully characterized by FT-IR, XRD, SEM, VSM, UV–Vis, DLS and EDS. Excellent yield, very short reaction time (7–10 min), operational simplicity, easy work-up procedure, avoidance of hazardous or toxic catalysts and organic solvents are the main advantages of this green methodology which makes it more economic than the other conventional methods.Superparamagnetic nanoparticles of modified vitamin B3 (Fe3O4@Niacin) represent a new, efficient and green biocatalyst for the one-pot synthesis of 2-amino-3-cyanopyridine derivatives via four-component condensation reaction between aldehydes, ketones, malononitrile, and ammonium acetate under microwave irradiation in water. This new magnetic organocatalyst was easily isolated from the reaction mixture by magnetic decantation using an external magnet and reused at least six times without significant degradation in the activity. The catalyst was fully characterized by FT-IR, XRD, SEM, VSM, UV-Vis, DLS and EDS. Excellent yield, very short reaction time (7–10 min), operational simplicity, easy work-up procedure, avoidance of hazardous or toxic catalysts and organic solvents are the main advantages of this green methodology which makes it more economic than the other conventional methods.
  PubDate: 2017-10-19T03:37:14.879197-05:
  DOI: 10.1002/aoc.4103
Sustainable chitosan/starch composite material for stabilization of
palladium nanoparticles: Synthesis, characterization and investigation of
catalytic behaviour of Pd@chitosan/starch nanocomposite in
Suzuki–Miyaura reaction
- Authors: Talat Baran; Nuray Yılmaz Baran, Ayfer Menteş
  Abstract: We fabricated a green chitosan/starch composite as support material for stabilization of palladium nanoparticles for the first time. The chemical structure of the sustainable palladium nanocomposite was investigated using various techniques. Characterization studies showed that the average dimensions of the palladium nanocomposite ranged between 16 and 21 nm. The synthesized palladium nanocomposite was employed in the synthesis of a series of biphenyl compounds via Suzuki–Miyaura cross-coupling reactions with an unconventional technique. All coupling reactions were conducted in very short reaction time and excellent biphenyl yields were obtained in the presence of the nanocomposite. The palladium catalyst was tolerant to a wide range of functional groups. We also investigated the recyclability and reusability of the palladium nanocomposite, and found that it could be used for seven successive cycles.Synthesis of Pd(0) nanocatalyst immobilized on chitosan/starch composite.Average dimensions of Pd nanocomposite particles were found as 16–21 nm.Pd nanocomposite exhibited superior catalytic activity.The catalyst showed good reusability potential.
  PubDate: 2017-10-16T03:57:06.891761-05:
  DOI: 10.1002/aoc.4075
Electrochemical transformations and evaluation of antioxidant activity of
some Schiff bases containing ferrocenyl and (thio-)phenol, catechol
fragments
- Authors: I.V. Smolyaninov; A.I. Poddel'sky, S.V. Baryshnikova, V.V. Kuzmin, E.O. Korchagina, M.V. Arsenyev, S.A. Smolyaninova, N.T. Berberova
  Abstract: Electrochemical transformations and antioxidant activity of some Schiff bases 1–5 containing ferrocenyl group and (thio-)phenol, catechol fragments were investigated. Compounds under investigation are: 2-(ferrocenylmethylene)amino)phenol (1), 2-((ferrocenylmethylene)amino)-4,6-di-tert-butylphenol (2), 2-((ferrocenylmethylene)amino)-thiophenol (3), 3-((ferrocenylmethylene)hydrazonomethyl)-4,6-di-tert-butylcatechol (4) and 2-((3,5-di-tert-butyl-4-hydroxybenzylidene)amino)thiophenol (5).In a case of compounds 1–3 it has shown that the sequence of electrochemical transformations leads to the products of intramolecular cyclization – 2-ferrocenylbenzoxazole (benzothiazole). o-Quinone formation occurs during the electrochemical oxidation of catechol-ferrocene 4 at the first anode stage. Electrochemical oxidation of the redox-active fragments in Schiff bases 1–4 can be achieved indirectly at a lower potential corresponding to the oxidation of ferrocenyl moiety, consequently these substances can reveal more pronounced antioxidant properties. The antioxidant activities of the compounds were evaluated using 2,2′-diphenyl-1-picrylhydrazyl radical (DPPH) assay, the reaction of 2,2′-azobis(2-amidinopropane hydrochloride) (AAPH) induced glutathione depletion (GSH), the oxidative damage of the DNA, the process of lipid peroxidation of rat (Wistar) brain homogenates in vitro. The compounds 1–4 in the antioxidant assays show effectiveness comparable with standard antioxidants (vitamin E, Trolox) and in some parameters superior to them. In the reaction of AAPH with the glutathione compounds 2–5 have a more pronounced protective activity than Trolox. Compounds 1–5 inhibit AAPH induced oxidation damage of the DNA. The more effective inhibitors of the lipid peroxidation process in vitro are molecules containing the bulky tert-butyl groups: 2 and 4 and Schiff base 3.Electrochemical oxidation of the redox-active fragments can be achieved indirectly at a low potential corresponding to the oxidation of ferrocenyl moiety. The Schiff bases can be activated at lower redox potentials and show pronounced antioxidant activity in comparison with the compounds containing phenolic or catecholic groups only.
  PubDate: 2017-10-16T03:47:33.954798-05:
  DOI: 10.1002/aoc.4121
New Ni(II), Pd(II) and Pt(II) complexes coordinated to azo pyrazolone
ligand with a potent anti-tumor activity: Synthesis, characterization, DFT
and DNA cleavage studies
- Authors: Eman A. Bakr; Gad B. Al-Hefnawy, Mohamed K. Awad, Hossam H. Abd-Elatty, Mohamed S. Youssef
  Abstract: The absolute necessity to fight some class of tumor is perceived as serious health concerns, so the discovery and development of effective anticancer agents are urgently needed. (E)-4-((2-hydroxyphenyl)diazenyl)-3-phenyl-1H-pyrazol-5(4H)-one, HL, and its Ni(II), Pd(II) and Pt(II) complexes were synthesized and the biological activity was evaluated for antitumor, antioxidant and antimicrobial activity as well as DNA cleavage. Their structures were assigned depending on the elemental analysis, conductivity, magnetic moment, spectral measurements (IR, 1HNMR, mass and UV–Vis) and thermal analysis. 3D molecular modeling using DFT method confirmed that the geometrical structures agree well with the suggested experimental ones. The antitumor activity was evaluated against four different cell lines using MTT assay. The ligand HL showed a potent cytotoxic activity compared to 5-fluorouracil as a reference drug. For metal complexes, the order of activity was: Pd(II) > Ni(II) > Pt(II). A remarkable antioxidant activity for the ligand HL was recorded. It was higher than that of the metal complexes. Results of antimicrobial experiments revealed that all compounds were moderate to highly active against selected bacterial strains but inactive as antifungal except Pd(II) which showed a moderate antifungal activity. Gel electrophoresis showed insignificant nucleases activity for the ligand or its metal complexes even in the presence of H2O2 providing protection of DNA from damage. The antitumor activity of our compounds may be not due to DNA cleavage but may be referred to a mechanism similar to that of 5-fluorouracil which interfere with DNA replication. The present work suggests the use of this ligand in the design and development of new anticancer drugs.An aryl azo pyrazolone ligand HL, and its Ni(II), Pd(II) and Pt(II) complexes were synthesized, characterized and biologically screened as antitumor, antioxidant and antimicrobial agents. 3D molecular modeling using DFT method confirmed that the geometrical structures agree well with the suggested experimental ones. The ligand HL showed a potent cytotoxic activity higher than the metal complexes. Gel electrophoresis showed insignificant nucleases activity for the ligand or its metal complexes even in presence of H2O2 providing protection of DNA from damage.
  PubDate: 2017-10-16T03:46:01.364581-05:
  DOI: 10.1002/aoc.4104
Six-coordinated vanadium(IV) complexes with tridentate task-specific ionic
liquid Schiff base ligands: Synthesis, characterization and effect of
ionic nature on catalytic activity
- Authors: Somayeh Azizi Talouki; Gholamhossein Grivani, Aliakbar Dehno Khalaji
  Abstract: By reaction of 5-(chloromethyl)salicylaldehyde with triphenylphosphine and N-methylimidazole in two separate reactions, salicylaldehydetriphenylphosphonium chloride (S2) and salicylaldehydemethylimidazolinium chloride (S3) were prepared. Reaction of 2-(aminomethyl)pyridine with these aldehydes resulted in the task-specific ionic liquid Schiff base ligands L1 and L2, respectively. Then six-coordinated vanadium(IV) Schiff base complexes of VO(acac)L1–4 were synthesized by reactions of these tridentate Schiff base ligands and VO(acac)2 in 1:1 stoichiometry. The aldehydes, ligands and VO(acac)L1–4 complexes were characterized using infrared, 1H NMR, 13C NMR, 31P NMR, UV–visible and mass spectroscopies, as well as elemental analysis. Paramagnetic property of the complexes was also studied using magnetic susceptibility measurements. The complexes were used as catalysts in epoxidation of cyclooctene and oxidation of methylphenyl sulfide and the reaction parameters were optimized. The effect of the ionic nature of the complexes was investigated in these oxidation reactions. The catalytic activity of the complexes could be varied by changing the ionic (cationic or anionic) character of VO(acac)L1–4 catalysts in which counter anion variation showed a greater effect than cationic moiety variation.By reaction of chlorosalicylaldehyde with triphenylphosphine and N-methylimidazole, salicylaldehydetriphenylphosphonium chloride (S2) and salicylaldehydemethylimidazolinium chloride (S3) were prepared. Reaction of 2-(aminomethyl)pyridine with these aldehydes resulted in task-specific ionic liquid Schiff base ligands L1 and L2. Then six-coordinated V(IV) Schiff base complexes of VO(acac)L1–4 were synthesized. The catalytic activity of these complexes was investigated; changing the ionic parts of them affected catalytic activity.
  PubDate: 2017-10-16T03:40:30.120463-05:
  DOI: 10.1002/aoc.4078
Novel water soluble bis(μ-chloro) bridged Cu(II) binuclear and
mononuclear complexes: Synthesis, characterization and biological
evaluation
- Authors: Thangavel Thirunavukkarasu; H. Puschmann, H.A. Sparkes, Karuppannan Natarajan, V.G. Gnanasoundari
  Abstract: A water soluble chloro bridged binuclear copper(II) complex (3) and mononuclear complex (4) have been synthesized from chloro substituted 2-oxo-1,2-dihydroquinolin-3-yl-methylene-2 hydroxybenzohydrazide 1 and 2 and CuCl2·2H2O. The structures of the complexes have been determined by single crystal X-ray diffraction. The binding interactions of the ligands and complexes with CT-DNA and protein have been evaluated by absorption and emission spectroscopic method. CT-DNA and ethidium bromide (EB) competitive studies revealed that the compounds could interact with CT-DNA through intercalation binding mode. Interactions of the compounds with BSA were also studied by UV−visible, fluorescence and synchronous fluorescence spectroscopic methods which showed that the compounds had a strong binding affinity with BSA through static quenching process. The cytotoxic effect of the compounds examined on cancer cell lines, such as A549 (lung cancer) and MCF7 (breast cancer) cell lines showed that all four compounds exhibited substantial cytotoxic activity.A water soluble chloro bridged binuclear copper(II) complex (3) and mononuclear complex (4) have been synthesized from chloro substituted 2-oxo-1,2-dihydroquinolin-3-yl-methylene-2 hydroxybenzohydrazide 1 and 2 and CuCl2·2H2O. The structures of the complexes have been determined by single crystal X-ray diffraction. The binding interactions of the ligands and complexes with CT-DNA and protein have been evaluated by absorption and emission spectroscopic method.
  PubDate: 2017-10-16T03:40:02.750613-05:
  DOI: 10.1002/aoc.4111
HPA decorated Halloysite Nanoclay: An efficient catalyst for the green
synthesis of Spirooxindole derivatives
- Authors: Samahe Sadjadi; Majid M. Heravi, Masoumeh Malmir, Baharak Masoumi
  Abstract: A novel heterogeneous catalyst, HPA@HNTs-IMI-SO3H, was designed and synthesized based on functionalization of halloysite nanotubes with ionic liquid and subsequent incorporation of heteropolyacid. The structure of the catalyst was studied and confirmed by using SEM/EDX, FTIR, XRD, ICP-AES, TGA, DTGA and BET. Moreover, the catalytic activity of HPA@HNTs-IMI-SO3H was investigated for promoting ultrasonic-assisted three-component reaction of isatines, malononitrile or cyanoacetic esters and 1,3-dicarbonyl compounds to afford corresponding spirooxindole in high yields and short reaction time. The reusability of the catalyst was also studied. Notably, the catalyst could be recovered and reused for three reaction runs. However, reusing for fourth reaction runs led to the decrease of the catalytic activity. Considering leaching test results, that observation was attributed to the leaching of heteropolyacids, which can be induced by ultrasonic irradiation.Heteropolyacid was immobilized on ionic liquid-functionalized halloysite nanoclay to furnish a novel heterogeneous and reusable catalyst, HPA@HNTs-IMI-SO3H, for promoting ultrasonic-assisted three-component reaction of isatines, malononitrile or cyanoacetic esters and 1,3-dicarbonyl compounds to afford corresponding spirooxindole in high yields and short reaction time.
  PubDate: 2017-10-16T03:33:48.712855-05:
  DOI: 10.1002/aoc.4113
Supported ruthenium hydride catalysts for direct conversion of alcohols to
carboxylic acids using styrene oxide as oxidant
- Authors: Moloud Ghafouri; Majid Moghadam, Kheirollah Mehrani, Anahita Daneshvar
  Abstract: In the present work, the ability of two ruthenium hydride catalysts supported on multiwall carbon nanotubes, [Ru–H@EDT–MWCNT], and gold nanoparticles cored triazine dendrimer, [Ru–H@AuNPs–TD], in the direct conversion of alcohols to carboxylic acids via transfer hydrogenation using styrene oxide as oxidant is reported. Different alcohols were successfully converted to their corresponding carboxylic acids. The results showed that these two heterogeneous catalysts are more efficient than the homogeneous counterpart. In addition, the catalysts were reused several times.Two ruthenium hydride catalysts supported on multiwall carbon nanotubes, [Ru–H@EDT–MWCNT], and gold nanoparticles cored triazine dendrimer, [Ru–H@AuNPs–TD], were applied in the direct conversion of alcohols to carboxylic acids via transfer hydrogenation using styrene oxide as oxidant.
  PubDate: 2017-10-16T03:33:10.952418-05:
  DOI: 10.1002/aoc.4048
Cu(II) immobilized on mesoporous organosilica as an efficient and reusable
- Authors: Zahra Nasresfahani; Mohammad Zaman Kassaee
  Abstract: Cu(II) immobilized on mesoporous organosilica nanoparticles (Cu2+@MSNs-(CO2−)2) has been synthesized, as a inorganic–organic nanohybrid catalyst, through a post-grafting approach. Its characterization is carried out by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Energy dispersive X-ray (EDX), Thermogravimetric/differential thermal analyses (TGA-DTA), and Nitrogen adsorption–desorption analysis. Cu2+@MSNs-(CO2−)2 exhibits high catalytic activity in the Biginelli reaction for the synthesis of a diverse range of 3, 4-dihydropyrimidin-2(1H)-ones, under mild conditions. The anchored Cu(II) could not leach out from the surface of the mesoporous catalyst during the reaction and it has been reused several times without appreciable loss in its catalytic activity.Preparation and catalytic activity of Cu2+@MSNs-(CO2−)2 in the Biginelli reaction for the synthesis of 3, 4-dihydropyrimidin-2(1H)-ones.
  PubDate: 2017-10-16T03:32:45.142151-05:
  DOI: 10.1002/aoc.4106
New anthracene based Schiff base ligands appended Cu(II) complexes:
Theoretical study, DNA binding and cleavage activities
- Authors: Ammavasai Gubendran; Gujuluva Gangatharan Vinoth Kumar, Mookkandi Palsamy Kesavan, Gurusamy Rajagopal, Periakaruppan Athappan, Jegathalaprathaban Rajesh
  Abstract: New anthracene based Schiff base ligands L1 and H(L2), their Cu(II) complexes [Cu(L1)Cl2] (1) and [Cu(L2)Cl] (2), (where L1 = N1,N2-bis(anthracene-9-methylene)benzene-1,2-diamine, L2 = (2Z,4E)-4-(2-(anthracen-9-ylmethyleneamino)phenylimino)pent-2-en-2-ol) have been prepared and characterized by elemental analysis, NMR, FAB-mass, EPR, FT-IR, UV–Vis and cyclic voltammetry. The electronic structures and geometrical parameters of complexes 1 and 2 were analyzed by the theoretical B3LYP/DFT method. The interaction of these complexes 1 and 2 with CT-DNA has been explored by using absorption, cyclic voltammetric and CD spectral studies. From the electronic absorption spectral studies, it was found that the DNA binding constants of complexes 1 and 2 are 8.7 × 103 and 7.0 × 104 M−1, respectively. From electrochemical studies, the ratio of DNA binding constants K+/K2+ for 2 has been estimated to be >1. The high binding constant values, K+/K2+ ratios more than unity and positive shift of voltammetric E1/2 value on titration with DNA for complex 2 suggest that they bind more avidly with DNA than complex 1. The inability to affect the conformational changes of DNA in the CD spectrum is the definite evidences of electrostatic binding by the complex 1. It can be assumed that it is the bulky anthracene unit which sterically inhibits these complexes 1 and 2 from intercalation and thereby remains in the groove or electrostatic. The complex 2 hardly cleaves supercoiled pUC18 plasmid DNA in the presence of hydrogen peroxide. The results suggest that complex 2 bind to DNA through minor groove binding.New Cu(II) complexes 1 and 2 of anthracene based Schiff base ligands. Characterization using various spectral and analytical tools. Geometrical parameters of Cu(II) complexes were analyzed by theoretical method. Complex 2 has effective DNA binding behavior than complex 1. Complex 2 comprises substantial DNA cleavage activity.
  PubDate: 2017-10-16T03:28:08.800083-05:
  DOI: 10.1002/aoc.4128
Pd-catalyzed Desulfitative reaction of Aryltrifluoroborates with sodium
Arenesulfinates in water
- Authors: Sheng Chang; Yong Bing Sun, Xiu Rong Zhang, Lin Lin Dong, He Yun Zhu, Hong Wei Lai, Dan Wang
  Abstract: An efficient procedure for the synthesis of biaryls was catalyzed by Pd(CH3CN)4(BF4)2 is reported. This Pd-catalyzed cross-coupling reaction of aryltrifluoroborates with sodium arenesulfinates was developed under mild and environmentally benign conditions, in water without any ligand or additive. The reaction gave a range of structurally diverse unsymmetrical bi-aryl molecules with excellent yields, in which the byproduct was sulfur dioxide. It is worth noting that this protocol is also applicable to many heterocyclic aromatics such as thiophene, furan, pyridine, quinoline, isoquinoline and indole.An efficient procedure for the synthesis of biaryls was catalyzed by Pd(CH3CN)4(BF4)2 is reported. This Pd-catalyzed cross-coupling reaction of aryltrifluoroborates with sodium arenesulfinates was developed under mild and environmentally benign conditions, in water without any ligand or additive. The reaction gave a range of structurally diverse unsymmetrical bi-aryl molecules including many heterocyclic aromatics with good yields, in which the byproduct was sulfur dioxide.
  PubDate: 2017-10-16T03:26:33.93373-05:0
  DOI: 10.1002/aoc.3970
HAp-encapsulated γ-Fe2O3-supported dual acidic heterogeneous catalyst for
highly efficient one-pot synthesis of benzoxanthenones and
3-pyranylindoles
- Authors: Leila Kheirkhah; Manouchehr Mamaghani, Asieh Yahyazadeh, Nosrat Ollah Mahmoodi
  Abstract: A novel method is reported for the synthesis of benzoxanthenone and 3-pyranylindole derivatives via one-pot three-component reactions using a newly synthesized HAp-encapsulated γ-Fe2O3-supported dual acidic heterogeneous catalyst, as a reusable and highly efficient nanocatalyst. In this protocol the use of the nanocatalyst provided a green, useful and rapid method to generate products in short reaction times (4–20 min) and in excellent yields (87–96%). The paramagnetic nature of the catalyst provided a simple, trouble-free and facile approach for the separation of the catalyst by applying an external magnet, and it could be used in eight cycles without significant loss in catalytic efficiency.A novel method is reported for the synthesis of benzoxanthenone and 3-pyranylindole derivatives via one-pot three-component reactions using a newly synthesized HAp-encapsulated γ-Fe2O3-supported dual acidic nanocatalyst as a heterogeneous, reusable and highly efficient catalyst.
  PubDate: 2017-10-16T03:24:13.325505-05:
  DOI: 10.1002/aoc.4072
A versatile supported silver for heterogeneously catalysed processes:
Synthesis of 3-Acyloxylindolines solvent-free conditions
- Authors: Seyed Mohsen Sadeghzadeh; Rahele Zhiani, Shokufe Emrani, Fatemeh Abedi
  Abstract: We have found that fibrous nanosilica (KCC-1) can used as a excellent support for the synthesis of highly sparse nanoparticles and has high surface area that was functionalized with Tetrathia-azacyclopentadecane (TTACP) groups acting as the strong performers so that the Ag nanoparticles were well-dispersed without aggregation on the fibers of the KCC-1 microspheres (KCC-1/TTACP/Ag). We enthusiasm to report one-pot synthesis of 3-Acyloxylindolines for first time from N-tosyl-2-vinylaniline, and benzoic acid in the presence of KCC-1/TTACP/Ag as a catalyst.We have found that fibrous nanosilica (KCC-1) can used as a excellent support for the synthesis of highly sparse nanoparticles and has high surface area that was functionalized with Tetrathia-azacyclopentadecane (TTACP) groups acting as the strong performers so that the Ag nanoparticles were well-dispersed without aggregation on the fibers of the KCC-1 microspheres (KCC-1/TTACP/Ag). We enthusiasm to report one-pot synthesis of 3-Acyloxylindolines for first time from N-tosyl-2-vinylaniline, and benzoic acid in the presence of KCC-1/TTACP/Ag as a catalyst.
  PubDate: 2017-10-16T03:21:08.854193-05:
  DOI: 10.1002/aoc.4130
Immobilization of nickel ions onto the magnetic nanocomposite based on
cross-linked melamine groups: Effective heterogeneous catalyst for
N-Arylation of Arylboronic acids
- Authors: Ali Pourjavadi; Nahid Keshavarzi, Firouz Matloubi Moghaddam, Seyed Hassan Hosseini
  Abstract: A new magnetic heterogeneous catalyst was synthesized by immobilization of nickel ions onto a cross-linked polymeric nanocomposite composed of cyanuric chloride, ethylenediamine and functionalized magnetic nanoparticles. The resulting nitrogen rich support was capable of adsorbing large amounts of nickel ions (1.20 mmol g−1). The synthesized catalyst was characterized using AAS, TEM, FT-IR, EDX, TGA, SEM, BET and XRD techniques. The performance of the prepared catalyst was investigated in the C-N coupling of arylamines with aryl boronic acids. The reaction was carried out under a mild condition and good to moderate to good yields of products was obtained using only 5.0 mol% of the catalyst. The catalyst was easily recovered and reused for at least 7 times without any significant loss of its activity.The robust synthesized catalysts based on poly melamine-like groups immobilized by nickel ions was used for N-arylation of arylboronic acids. The advantages of this catalyst are high loading level, great stability, magnetic recyclability and high product yields.
  PubDate: 2017-10-16T03:19:10.319224-05:
  DOI: 10.1002/aoc.4107
Cobalt(II)–metformin complexes containing α-diimine/α-diamine as
auxiliary ligand: DNA binding properties
- Authors: P. Vasantha; B. Sathish Kumar, B. Shekhar, P.V. Anantha Lakshmi
  Abstract: The cobalt(II) complexes [Co(Cl)2(met)(o-phen)] (1), [Co(Cl)2(en)(met)] (2) and [Co(Cl)2(met)(opda)] (3) (met = metformin, o-phen = ortho-phenanthroline, en = ethylenediamine, opda = ortho-phenylenediamine) were synthesized and characterized using liquid chromatography–mass spectrometry, elemental analysis, molar conductance measurements, thermal analysis, infrared spectroscopy, magnetic moment measurements, electronic spectroscopy and X-ray diffraction. The metal centre was found to be in an octahedral geometry. UV–visible absorption, fluorescence and viscosity measurements were conducted to assess the interaction of the complexes with calf thymus DNA. The complexes showed absorption hyperchromism in UV–visible spectra with DNA. The binding constants from UV–visible absorption studies were 1.38 × 105, 2.1 × 105 and 3.1 × 105 M−1 for 1, 2 and 3, respectively, and Stern–Volmer quenching constants from fluorescence studies were 0.146, 0.176 and 0.475, respectively. Viscosity measurements revealed that the binding of the complexes with DNA could be surface binding, mainly due to groove binding. The activities of the complexes in DNA cleavage decrease in the order 3 > 2 > 1. The complexes were docked into DNA topoisomerase II using Discovery Studio 2.1 software.DNA binding studies suggest that cobalt(II)–metformin complexes containing α-diimine/α-diamine as auxiliary ligands bind to DNA via groove binding.
  PubDate: 2017-10-16T03:18:47.930883-05:
  DOI: 10.1002/aoc.4074
Cu(II) immobilized on guanidinated epibromohydrin-functionalized
γ-Fe2O3@TiO2 (γ-Fe2O3@TiO2-EG-Cu(II)): A highly efficient magnetically
separable heterogeneous nanocatalyst for one-pot synthesis of highly
substituted imidazoles
- Authors: Mahdi Nejatianfar; Batool Akhlaghinia, Roya Jahanshahi
  Abstract: A simple, efficient and eco-friendly procedure has been developed using Cu(II) immobilized on guanidinated epibromohydrin-functionalized γ-Fe2O3@TiO2 (γ-Fe2O3@TiO2-EG-Cu(II)) for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles, via the condensation reactions of various aldehydes with benzil and ammonium acetate or ammonium acetate and amines, under solvent-free conditions. High-resolution transmission electron microscopy analysis of this catalyst clearly affirmed the formation of a γ-Fe2O3 core and a TiO2 shell, with mean sizes of about 10–20 and 5–10 nm, respectively. These data were in very good agreement with X-ray crystallographic measurements (13 and 7 nm). Moreover, magnetization measurements revealed that both γ-Fe2O3@TiO2 and γ-Fe2O3@TiO2-EG-Cu(II) had superparamagnetic behaviour with saturation magnetization of 23.79 and 22.12 emu g−1, respectively. γ-Fe2O3@TiO2-EG-Cu(II) was found to be a green and highly efficient nanocatalyst, which could be easily handled, recovered and reused several times without significant loss of its activity. The scope of the presented methodology is quite broad; a variety of aldehydes as well as amines have been shown to be viable substrates. A mechanism for the cyclocondensation reaction has also been proposed.A simple, efficient and eco-friendly procedure has been developed using γ-Fe2O3@TiO2-EG-Cu(II) for the synthesis of 2,4,5-trisubstituted and 1,2,4,5-tetrasubstituted imidazoles, via the condensation reactions of various aldehydes with benzil and ammonium acetate or ammonium acetate and amines, under solvent-free conditions. Fe2O3@TiO2-EG-Cu(II) was found to be a green and highly efficient nanocatalyst, which could be easily handled, recovered and reused several times without significant loss of activity.
  PubDate: 2017-10-16T03:16:18.570775-05:
  DOI: 10.1002/aoc.4095
Fabrication of nanoporous polymeric crystalline TiO2 composite for
photocatalytic degradation of aqueous organic pollutants under visible
light irradiation
- Authors: Dasheng Gao; Ningning Liu, Weiwei Li, Yide Han
  Abstract: A nanoporous polymeric crystalline TiO2 composite (TiO2/PDVB-MA) has been successfully synthesized through an in situ synthesis method using divinylbenzene (DVB), methacrylic acid (MA) and tetrabutyl titanate. The experimental results showed that TiO2 nanoparticles composed of the mixture phases of anatase and rutile were homogeneously dispersed into the PDVB-MA support. The TiO2/PDVB-MA composite was used as photocatalyst for Rhodamine B (RhB), bisphenol A and 2,4,6-trichlorophenol degradation under visible light irradiation. More interestingly, the excellent photocatalytic performance of the composite was observed with regard to RhB and bisphenol A, which might be ascribed to the synergistic effect between TiO2 nanoparticles and PDVB-MA. Moreover, TiO2/PDVB-MA composite could be recycled at least four times in the removal of RhB, suggesting that it is a promising photocatalyst to catalyze the degradation of organic pollutants under visible light irradiation.A nanoporous polymeric crystalline TiO2 composite (TiO2/PDVB-MA) has been successfully synthesized through an in situ synthesis method using divinylbenzene, methacrylic acid and tetrabutyl titanate. The TiO2/PDVB-MA composite possesses excellent adsorptive performance and photocatalytic activity for organic pollutants degradation under visible light irradiation. This phenomenon is attributed to the rich porous structure of PDVB-MA support and the synergistic effect between TiO2 nanoparticles and support.
  PubDate: 2017-10-16T03:11:13.527891-05:
  DOI: 10.1002/aoc.4119
Heck and oxidative boron Heck reactions employing Pd(II) supported
amphiphilized polyethyleneimine-functionalized MCM-41 (MCM-41@aPEI-Pd) as
an efficient and recyclable nanocatalyst
- Authors: Seyed Farshad Motevalizadeh; Masoumeh Alipour, Fatemeh Ashori, Alireza Samzadeh-Kermani, Hosein Hamadi, Mohammad Reza Ganjali, Hamideh Aghahosseini, Ali Ramazani, Mehdi Khoobi, Elham Gholibegloo
  Abstract: A novel nanocatalyst was developed based on covalent surface functionalization of MCM-41 with polyethyleneimine (PEI) using [3-(2,3-Epoxypropoxy)propyl] trimethoxysilane (EPO) as a cross-linker. Amine functional groups on the surface of MCM-41 were then conjugated with iodododecane to render an amphiphilic property to the catalyst. Palladium (II) was finally immobilized onto the MCM-41@PEI-dodecane and the resulted MCM-41@aPEI-Pd nanocatalyst was characterized by FT-IR, TEM, ICP-AES and XPS. Our designed nanocatalyst with a distinguished core-shell structure and Pd2+ ions as catalytic centers was explored as an efficient and recyclable catalyst for Heck and oxidative boron Heck coupling reactions. In Heck coupling reaction, the catalytic activity of MCM-41@aPEI-Pd in the presence of triethylamine as base led to very high yields and selectivity. Meanwhile, the MCM-41@aPEI-Pd as the first semi-heterogeneous palladium catalyst was examined in the C-4 regioselective arylation of coumarin via the direct C-H activation and the moderate to excellent yields were obtained toward different functional groups. Leaching test indicated the high stability of palladium on the surface of MCM-41@aPEI-Pd as it could be recycled for several runs without significant loss of its catalytic activity.Functionalizing the surfaces of MCM-41 with polyethylenimine (PEI) and [3-(2,3-epoxypropoxy)propyl]trimethoxysilane (EPO) and its amphiphilization by Iodododecane conjugation, then the adsorption of Pd inside its shell to produce MCM-41@aPEI-Pd, as an efficient, selective and stable nanocatalyst for the Heck and oxidative boron Heck reactions.
  PubDate: 2017-10-16T03:02:23.641966-05:
  DOI: 10.1002/aoc.4123
Synthesis and catalytic evaluation of Fe3O4/MWCNTs nanozyme as recyclable
peroxidase mimetics: Biochemical and physicochemical characterization
- Authors: Navvabeh Salarizadeh; Minoo Sadri, Reza H. Sajedi
  Abstract: In this research, the nanocomposite of multiwalled carbon nanotubes and magnetic metal oxide nanoparticles (Fe3O4/MWCNTs), as enzyme mimetic, was synthesized using an in situ chemical reduction method. The structure, composition and morphology of the prepared Fe3O4/MWCNT nanocomposite materials were characterized using X-ray diffraction, FT-IR and scanning electron microscopy with energy dispersive X-ray spectroscopy, respectively. The magnetic properties of the nanocomposite were investigated by the vibrating sample magnetometer. A colorimetric system involving nanozyme, phenol/4-aminoantipyrine and H2O2 was utilized for the determination of peroxidase mimetic catalytic assay. The obtained results confirmed that the synthesis of Fe3O4/MWCNTs nanostructures was successful. It was found that Fe3O4/MWCNTs nanohybrid exhibited peroxidase-like activity without any pH limitation. Colorimetric data demonstrated that the prepared nanocatalyst had higher catalytic activity toward H2O2 than MWCNTs. The kinetic parameters of the nanozyme, Km and Vmax, were estimated to be 8.3 mm and 1.4 mm min−1, respectively. The Fe3O4/MWCNTs nanostructures were also successfully applied for glucose detection. In addition, peroxidase-like activity of the nanozyme increased in the presence of butyl-imidazolium bromide ionic liquid. These biomimetic catalysts have some advantages, such as simplicity, stability, reusability and cost effectiveness, which makes them great candidates to be used in various fields of biotechnology applications.A magnetic nanozyme, Fe3O4/MWCNTs, as a peroxidase mimetics was fabricated using in situ chemical reduction method and characterized. Finally the peroxidase-like catalytic activity of nanocatalyst was investigated with the oxidation of peroxidase substrate, 4-aminoantipyrine (4-AAP)/phenol in the presence of H2O2 reagent to the pink colored quinoneimine product which provides a colorimetric detection of H2O2. Also, a combination of the peroxidase-like catalytic activity of the Fe3O4/MWCNTs nanozyme with glucose oxidase, allowed the system of a sensitive colorimetric assay for glucose monitoring.
  PubDate: 2017-10-16T03:01:58.664257-05:
  DOI: 10.1002/aoc.4018
Ferrocene-substituted bis(ethynyl)anthracene compounds as anticancer
agents
- Authors: Ajeet Singh; Pratibha Kumari, Abhinav Raghuvanshi, Shaikh M. Mobin, Pradeep Mathur
  Abstract: Three compounds (1–3) were synthesized, where ethynylferrocene is substituted at different positions of anthracene and anthraquinone, and their biological properties were investigated. Compounds 1–3 were characterized using NMR and mass spectroscopies and confirmed by their single-crystal X-ray structure. They were also characterized from electronic and photophysical properties. All three crystal structures were optimized using density functional theory calculations. The presence of C–H⋅⋅⋅π interactions in 1–3 leads to the formation of two- and three-dimensional networks. The bioactivity of 1–3 was expressed by molecular docking with various cancerous proteins, which participated in progression of cancer. Compound 2 displayed the best interaction with cancer-related Aurora A protein in terms of both binding energy (−10.61 kcal mol−1) as well as inhibition constant (16.74 nM). The molecular docking result also coincides with cytotoxicity on cancer cell lines (A375, HeLa) and DNA/protein binding affinity.The bioactivity of ethynylferrocene-based compound 2 led to the best interaction with cancer-related Aurora A protein in terms of both binding energy (−10.61 kcal mol−1) as well as inhibition constant (16.74 nM). The molecular docking result further coincides with cytotoxicity for cancer cell lines and DNA/protein binding affinity.
  PubDate: 2017-10-16T03:00:59.346695-05:
  DOI: 10.1002/aoc.4071
Effect of surface modification with various thiol compounds on colloidal
stability of gold nanoparticles
- Authors: Mahsa Mazloomi-Rezvani; Mehdi Salami-Kalajahi, Hossein Roghani-Mamaqani, Amin Pirayesh
  Abstract: Gold nanoparticles (AuNPs) are attractive materials due to their special optical and electronic properties. However, they tend to aggregate particularly in the presence of thiol-containing compounds. In this study, to investigate the effect of surface conjugation with thiol-containing compounds on colloidal stability, thiol compounds with various structures as modifying agents were used. To this end, AuNPs were synthesized and stabilized by trisodium citrate in aqueous solution, and then modified with thiol-containing compounds, namely cysteamine hydrochloride (MEA, containing primary amine groups), 2-mercaptoethanol (BME, containing hydroxyl groups), 1-dodecanthiol (LCA, containing long-chain alkyl groups) and thioglycolic acid (TGA, containing carboxylic acid groups). We studied the effect of thiol ligands on solution stability of colloidal AuNPs and on the formation of aggregates originating from the modification process using UV–visible spectroscopy, dynamic light scattering, field emission scanning electron microscopy and transmission electron microscopy. Results showed that surface modification with MEA, BME and LCA led to the formation of aggregates. However, conjugation with TGA showed a concentration-dependent behaviour: surface modification with low concentration resulted in the formation of aggregates whereas that with high concentration of TGA did not disturb the colloidal stability of AuNPs. Finally, the effect of surface modification on temperature increase of solutions originating from infrared light irradiation was studied, where the temperature increase depends on the surface-modifying compound.Colloidal AuNPs were conjugated with various thiol-containing compounds those had different functional groups. Colloidal stability of as-synthesized and modified nanoparticles were investigated in aqueous medium. Also, temperature rise of colloidal nanoparticles due to IR irradiation originated from SPR of nanoparticles were studied.
  PubDate: 2017-10-16T02:56:20.861844-05:
  DOI: 10.1002/aoc.4079
Synthesis and characterization of sodium polyaspartate-functionalized
silica-coated magnetite nanoparticles: A heterogeneous, reusable and
magnetically separable catalyst for the solvent-free synthesis of
2-amino-4H-chromene derivatives
- Authors: Akbar Mobinikhaledi; Hassan Moghanian, Masoumeh Ghanbari
  Abstract: An efficient and facile method was used for the synthesis of sodium polyaspartate-functionalized silica-coated magnetite nanoparticles. The structure of this nanoparticle was characterized by scanning electron microscopies, X-ray diffraction, energy-dispersive X-ray, Fourier transform infrared spectroscopies and vibrating sample magnetometry. Then, this compound was used as a reusable heterogeneous catalyst for green synthesis of 2-amino-4H-chromene derivatives via one-pot three-component reactions. This novel material showed great catalytic performance and the reactions which were carried out by this catalyst showed good to excellent yields. Besides, the catalyst could easily be separated from the reaction mixture by using an external magnetic field and it was stable enough to reuse several times without any significant reduction in the yield of reactions. Eco-friendliness, high purity of the desired products, short reaction time and easy workup procedure can be mentioned as the other advantages of this method.The synthesis of sodium polyaspartate-functionalized silica-coated magnetite nanoparticles and its efficient and application as a magnetically separable catalyst for green synthesis of 2-amino-4H-chromene derivatives via one-pot three-component reactions are reported.
  PubDate: 2017-10-16T02:50:38.885015-05:
  DOI: 10.1002/aoc.4108
Ligand-free Mizoroki–heck reaction using reusable modified graphene
oxide-supported Pd(0) nanoparticles
- Authors: Hojat Veisi; Najibeh Mirzaee
  Abstract: Palladium nanoparticles supported on graphene oxide surfaces modified with metformin was found to be an effective and recyclable nanocatalyst in Mizoroki–Heck coupling reactions under aerobic conditions without requiring any phosphine or ligand coordination. Excellent product yields were achieved with a wide variety of substrates and the catalyst could be recycled seven times without any noticeable loss of its catalytic activity.Palladium nanoparticles supported on graphene oxide surfaces modified with metformin was found to be an effective and recyclable nanocatalyst in Mizoroki–Heck coupling reactions.
  PubDate: 2017-10-16T02:41:39.818226-05:
  DOI: 10.1002/aoc.4067
Dodecatungstocobaltate heteropolyanion encapsulation into MIL-101(Cr)
metal–organic framework scaffold provides a highly efficient
heterogeneous catalyst for methanolysis of epoxides
- Authors: Afsaneh Marandi; Shahram Tangestaninejad, Majid Moghadam, Valiollah Mirkhani, Adam Mechler, Iraj Mohammadpoor-Baltork, Farnaz Zadehahmadi
  Abstract: A heterogeneous catalyst was synthesized by encapsulation of a Keggin-type heteropolytungstate, potassium dodecatungstocobaltate trihydrate, K5[CoW12O40]·(Co-POM), into chromium(III) terephthalate (MIL-101). Encapsulation was achieved via a ‘build bottle around ship’ strategy in aqueous media, following a hydrothermal method. The structure of the resulting crystalline solid was characterized using X-ray diffraction, correlated with Fourier transform infrared and UV–visible spectroscopy. The metal content was analysed using optical emission spectroscopy. Transmission electron microscopy was used to measure particle size and N2 adsorption in a Brunauer–Emmett–Teller instrument to characterize the specific surface area. The catalytic activity was investigated using methanolysis of epoxides under mild conditions as a test reaction. The turnover frequency of the heterogeneous Co-POM@MIL-101 catalyst was more than 20 times higher than that of the homogeneous Co-POM catalyst. The Co-POM@MIL-101 catalyst was reused several times with negligible leaching of Co-POM and with no considerable loss of its initial efficiency. The simplicity of preparation, extraordinary stability and high reactivity make Co-POM@MIL-101 an exceptional catalytic matrix that is easily separable from reaction media.A heterogeneous catalyst was prepared using a one-pot procedure to encapsulate dodecatungstocobaltate heteropolyanion (Co-POM) into MIL-101(Cr) metal–organic framework. The resultant hybrid material, Co-POM@MIL-101, exhibited superior catalytic activity in the methanolysis of epoxides.
  PubDate: 2017-10-11T23:21:29.479765-05:
  DOI: 10.1002/aoc.4065
Regioselective lithiation of 1-benzylpyrazole derivatives: Synthesis of
amides derived from pyrazole
- Authors: Agnieszka Górska; Tomasz Kliś, Janusz Serwatowski
  Abstract: A series of brominated 1-benzylpyrazoles were deprotonated at the pyrazole 5-position or the benzylic position on treatment with lithium diisopropylamide in tetrahydrofuran at low temperature. The obtained organolithium intermediates were subjected to reaction with Me3SiCl, t-BuNCO, ClCONEt2 or ClCON(i-Pr)2 affording the respective silanes or amides after hydrolysis.A series of brominated 1-benzylpyrazoles were deprotonated at the pyrazole 5-position or at benzylic position on treatment with lithium diisopropylamide in tetrahydrofuran at low temperature. The obtained organolithium intermediates were subjected to reaction with Me3SiCl or t-BuNCO affording the respective silanes or amides after hydrolysis.
  PubDate: 2017-10-11T23:20:32.192881-05:
  DOI: 10.1002/aoc.4027
Spectroscopic studies, structural characterization and electrochemical
studies of two cobalt (III) complexes with tridentate hydrazone Schiff
base ligands: Evaluation of antibacterial activities, DNA-binding, BSA
interaction and molecular docking
- Authors: Roghayeh Fekri; Mehdi Salehi, Asadollah Asadi, Maciej Kubicki
  Abstract: Co(III) complexes of tridentate Schiff base ligands derived from N-(2-hydroxybenzylideneamino)benzamide (H2L1) and 2-(2-hydroxybenzylidene)hydrazine-1-carboxamide (H2L2) were synthesized and characterized using IR, Raman, 1H–NMR and UV–Vis spectroscopies. X-ray single crystal structures of complexes 1 and 2 have also been determined, and it was indicated that these Co(III) complexes are in a distorted octahedral geometry. The cyclic voltammetry (CV) of the complexes indicates an irreversible redox behavior for both complexes 1 and 2. The antibacterial effects of the synthesized compounds have been tested by minimum inhibitory concentration and minimum bactericidal concentration methods, which suggested that the metal complexes exhibit better antibacterial effects than the ligands against Gram-positive bacteria. The effects of the drug (drug = ligands and complexes) on bovine serum albumin (BSA) were examined using circular dichroism (CD) spectropolarimetry, and it was revealed that the BSA (BSA, as a carrier protein) secondary structure changed in the presence of the drug. Interaction of the drug with calf-thymus DNA (CT-DNA) was investigated by UV–Vis absorption, fluorescence emission, CV and CD spectroscopy. Binding constants were determined using UV–Vis absorption. The results indicated that the studied Schiff bases bind to DNA, with the hyperchromic effect and non-intercalative mode in which the metal complexes are more effective than ligands. Furthermore, molecular docking simulation was used to obtain the energetic and binding sites for the interaction of the complexes with Mycobacterium tuberculosis enoyl-acyl carrier protein reductase (InhA), and results showed that complex 1 has more binding energy.Co(III) complexes of tridentate Schiff base ligands derived from N-(2-hydroxybenzylideneamino)benzamide (H2L1) and 2-(2-hydroxybenzylidene)hydrazine-1-carboxamide (H2L2) were synthesized and characterized using IR, Raman, 1H NMR, and UV–Vis spectroscopies. X-ray single crystal structures of complexes 1 and 2 were also determined. Electrochemical properties of complexes 1 and 2 were investigated in acetonitrile. These compounds were tested for antibacterial activity against Gram-positive and Gram-negative bacteria. Also, the details of DNA-binding and BSA-binding of these compounds were reported. Finally, molecular docking studies were performed to illustrate the binding mode of the complexes.
  PubDate: 2017-10-11T08:10:43.869406-05:
  DOI: 10.1002/aoc.4019
Versatile cobalt complexes for initiating immortal ring-opening
polymerization (ROP) of lactide (LA), mediating living radical
polymerization of t-butyl acrylate (tBA) and catalyzing copolymerization
of LA and tBA by combination of ROP and organometallic-mediated radical
polymerization
- Authors: Jianing Zhang; Baolong Wang, Liying Wang, Junmin Sun, Yongfeng Zhang, Zhenzhu Cao, Zhenqiang Wu
  Abstract: Low-cost, highly active and versatile amino-bis(phenolate) cobalt complexes are developed. The cobalt complexes can control living polymerization of different categories of monomers including lactide (LA) by immortal ring-opening polymerization in argon and even in air and acrylate via living radical polymerization (LRP). The cobalt-based catalysts were used for copolymerization of LA and acrylate. The immortal polymerization of LA using the cobalt complexes as initiators proceeds in argon and even in air and without the requirement for extensive drying techniques or inert atmosphere whilst retaining end-group fidelity. The cobalt complexes are used to mediate LRP of t-butyl acrylate (tBA) in methanol. The block copolymerization of LA and tBA catalyzed by single-site cobalt organometallic catalyst is also reported for the first time. This cobalt system offers a versatile and green way to produce homopolymers and block copolymers.Low-cost, highly active and versatile cobalt complexes can control immortal ring-opening polymerization (ROP) of lactide (LA), living radical polymerization of t-butyl acrylate (tBA) and unexpected copolymerization of LA and tBA by combination of ROP and organometallic-mediated radical polymerization (OMRP). The discovery of efficient, productive, nontoxic, versatile and inexpensive catalysts is a crucial requirement for sustainable growth of the green chemical industry.
  PubDate: 2017-10-11T08:10:33.172878-05:
  DOI: 10.1002/aoc.4077
Three-dimensional coordination polymers based on trimethyltin cation with
nicotinic and isonicotinic acids as anticancer agents
- Authors: Safaa El-din H. Etaiw; Tarek A. Fayed, Mohamed M. El-bendary, Hassan Marie
  Abstract: Two new coordination polymers, namely [Me3Sn(INA)] (CP1) and [Me3Sn(NA)] (CP2), where INA = isonicotinic acid and NA = nicotinic acid, were characterized using infrared, UV–visible and NMR spectroscopies, thermogravimetric analysis and single-crystal X-ray analyses. The structure of CP1 consists of a one-dimensional coordinated chain which is further extended creating a two-dimensional layer via hydrogen bonds. The two-dimensional layers propagate along the corresponding planes creating a three-dimensional framework by hydrogen bonding and edge-to-face π–π stacking. The asymmetric unit of CP2 contains one tin atom and one NA ligand exhibiting 1:1 stoichiometry. The structure of CP2 extends through coordination bonds to form a one-dimensional zigzag chain which further extends to create a three-dimensional network via crossing chains and hydrogen bonds. The tin atoms acquire distorted trigonal bipyramid (TBPY-5) geometry. CP1 and CP2 were designed to investigate their cytotoxic properties against various human cancer cell lines: hepatocellular carcinoma, mammary gland breast cancer, human prostate cancer and colorectal carcinoma. The compounds are good anticancer agents against the tested cell lines. Also they were screened for their antioxidant, anti-haemolytic, antibacterial and antifungal activities.The three-dimensional network structure of two new coordination polymers, [Me3Sn(INA)] (CP1) and [Me3Sn(NA)] (CP2), is developed by extensive hydrogen bonds and π–π stacking. CP1 and CP2 are good anticancer agents against various human cancer cell lines. They were screened for their antioxidant, anti-haemolytic, antibacterial and antifungal activities.
  PubDate: 2017-10-11T08:10:21.583962-05:
  DOI: 10.1002/aoc.4066
Synthesis and characterization of Ni(II) complexes bearing of
2-(1H–benzimidazol-2-yl)-phenol derivatives as highly active catalysts
for ethylene oligomerization
- Authors: Marzieh Haghverdi; Azadeh Tadjarodi, Naeimeh Bahri-Laleh, Mehdi Nekoomanesh-Haghighi
  Abstract: Novel Ni(II) complexes of 2-(1H–benzimidazol-2-yl)-phenol derivatives (HLx: x = 1–5; C1–C5) have been synthesized and characterized. In the mononuclear complexes, the ligands were coordinated as bidentate, via one imine nitrogen and the phenolate oxygen atoms. The structures of the compounds were confirmed on the basis of FT-IR, UV–Vis, 1H-, 13C–NMR, inductively coupled plasma and elemental analyses (C, H and N). The purity of these compounds was ascertained by melting point (m.p.) and thin-layer chromatography. The geometry optimization and vibrational frequency calculations of the compounds were performed using Gaussian 09 program with B3LYP/TZVP level of theory. All Ni(II) complexes were activated with diethylaluminum chloride (Et2AlCl), so that C2 showed the highest activity [6600 kg mol−1 (Ni) h−1], where the ligand contains a chlorine substituent. Oligomers obtained from the complexes consist mainly of dimer and trimer, and also exhibit high selectivity for linear 1-butene and 1-hexene. Both the steric and electronic effects of coordinative ligands affect the catalytic activity and the properties of the catalytic products.Novel Ni(II) complexes of 2-(1H-Benzimidazol-2-yl)-phenol derivatives (HLx: x = 1–5) (C1-C5) have been synthesized and characterized. All Ni(II) complexes were activated with diethylaluminum chloride, (Et2AlCl), so that C2 showed the highest activity (6600 Kg. mol−1 (Ni).h−1) with a chlorine substituent. Oligomers obtained from the complexes consist mainly of dimer and trimer, and also exhibit high selectivity for linear 1-butene and 1-hexene.
  PubDate: 2017-10-11T08:10:16.423668-05:
  DOI: 10.1002/aoc.4015
Pd nanoparticles immobilized on magnetic chitosan as a novel reusable
catalyst for green Heck and Suzuki cross-coupling reaction: In water at
room temperature
- Authors: Abdol R. Hajipour; Ali R. Sadeghi, Zahra Khorsandi
  Abstract: A novel type of magnetically responsive chitosan nanocomposite was successfully synthesized as a green and high powerful palladium-based heterogeneous catalyst and its efficiency in Heck and Suzuki cross-coupling was evaluated. This catalyst promote a large library of functional substrates of these reactions under mild and sustainable conditions (water or ethanol as solvent, at room temperature, in significantly short reaction time (20 minutes)) and stand as recyclable, metal scavenging catalytic systems.Development of Heck and Suzuki cross-coupling reaction in safe and green medium was occurred using a novel magnetically chitosan nanocomposite as a green and high powerful palladium-based heterogeneous catalyst.
  PubDate: 2017-10-05T02:05:51.519992-05:
  DOI: 10.1002/aoc.4112
Synthesis, characterization and solid-phase extraction properties of novel
bis(diazo-azomethine) ligands supported on mesoporous silica
- Authors: Serhan Uruş; Muharrem Karabörk, Hüseyin Köksal
  Abstract: The novel mesoporous silica-supported bis(diazo-azomethine) compounds have been synthesized and characterized successively. In the first step, 1,3-phenylenedimethanamine and 4,4′-diaminodiphenylmethane were diazotized, and the obtained bis(diazonium) cations were coupled with 2,4-dihydroxybenzaldehyde. The synthesized bis(diazo-carbonyl) compounds, 5,5′-((1,3-phenylenebis(methylene))bis(diazene-2,1-diyl))bis(2,4-dihydroxybenzaldehyde) (A1) and 5,5′-((methylenebis(4,1-phenylene))bis(diazene-2,1-diyl))bis(2,4-dihydroxybenzaldehyde) (A2) were chemically supported on amino-modified silica-gel (as L1 and L2). Elemental analysis, liquid chromatography-mass spectroscopy, liquid-phase NMR (1H and 13C) and solid-phase NMR (CP-MAS 29Si and 13C), FT-IR, TG/DTA, scanning electron microscopy and energy-dispersive X-ray spectroscopy techniques were used for characterizations of all the synthesized compounds. The syringe and batch techniques were applied for the solid-phase extraction properties of Pb(II), Cu(II), Cd(II) and Cr(III) ions using an inductively coupled plasma-atomic emission spectroscopy instrument. The recoveries of Pb(II), Cu(II), Cd(II) and Cr(III) ions have been achieved to 95–99% with the (RSDs) of ± 2–3% in optimum conditions.Synthesis of novel bis(diazo-azomethine) ligands supported on mesoporous silica.Effective adsorbents for metal ions in water samples.
  PubDate: 2017-10-04T03:47:20.440391-05:
  DOI: 10.1002/aoc.4022
Oxygen bridged Homobinuclear Mn(II) compounds with Anthranilic acid:
Theoretical calculations, oxidation and catalase activity
- Authors: Esra Su; Alaettin Guven, Ibrahim Kani
  Abstract: Two new homobinuclear manganese compounds with mixed ligands, [Mn2(μ1,1–2-NH2C6H4COO)2(phen)4](ClO4)2(CH3OH) (1), and [Mn2(μ1,3–2-NH2C6H4COO)2(bipy)4](ClO4)2 (2) (NH2C6H4COOH = anthranilic acid, bipy = 2,2′-bipyridine, phen = 1,10- phenanthroline) were synthesized and thoroughly characterized by elemental analysis, IR, UV and single crystal X-ray crystallography. X-ray structure analysis shows that in the mono- and bidentate carboxylate bridged compounds, Mn–Mn distances of 1 and 2 are 3,461 Å, and 4,639 Å, respectively. The energy of the compounds was determined with a DFT (Density Functional Theory) calculation on B3LYP/6-31G(d,p) optimized geometry by using the B3LYP/6-31G(d,p) basis set. These compounds acts as biomimetic catalyst and show catalase-like activity for the hydrogen peroxide dismutation at room temperature in different solvents with remarkable activity (TOF, Turnover frequency = mol of subst./(mol of cat. × time)) up to 12640 h−1 with 1, and 17910 h−1 with 2 in Tris–HCl buffer). Moreover, the catalytic activity of 1 and 2 has been studied for oxidation of alcohols (cinnamyl alcohol, benzyl alcohol, cyclohexanol, 1-octanol and 1-heptanol) and alkenes (cyclohexene, styrene, ethyl benzene, 1-octene and 1-hexene) in a homogeneous catalytic system consisting t-butylhydroperoxide (TBHP) as an oxidant in acetonitrile. Both compounds exhibited very high activity in the oxidation of cyclohexene to cyclohexanone (~80% selectivity, ~99% conversion in 1 h, TOF = 243 h−1 and 226 h−1) and cinnamyl alcohol to cinnamaldehyde (~64% selectivity) as the main product with very high TOF value (9180 h−1 and 13040 h−1 in the first minute of reaction) (~100% conversion in 0.5 h) with TBHP at 70 °C in acetonitrile, for 1 and 2, respectively.Two biomimetic Mn(II) compounds of 2,2′-bipyridine/1,10-phenanthroline and anthranilic acid have been synthesized, characterized and the catalase-like and oxidation activity tested in different conditions. The results showed that the compounds are very active (TOF up to 12640 h−1 with 1, and 17910 h−1 with 2) in tris–HCl buffer. Both compounds have also activity on oxidation of alcohols and alkenes.
  PubDate: 2017-10-04T03:42:48.259549-05:
  DOI: 10.1002/aoc.4105
Synthesis, characterization and application of graphene palladium
porphyrin as a nanocatalyst for the coupling reactions such as:
Suzuki-Miyaura and Mizoroki-heck
- Authors: Kiumars Bahrami; Soheila Nakhjiri Kamrani
  Abstract: The palladium(II)-coordinated 5,10,15,20-tetrakis-(4-hexyloxyphenyl)-porphyrin as a macrocyclic palladium complex was covalently grafted to the surface of graphene oxide (denoted as GO-CPTMS@Pd-TKHPP). GO-CPTMS@Pd-TKHPP was characterized using microscopic and spectroscopic techniques for confirmation of functionalization. The synthesized catalyst was checked in the Suzuki-Miyaura and the Mizoroki-Heck coupling reactions. The catalyst is very easy to handle, environmentally safe and economical. Also, this catalytic system shows high catalytic activity and the yields of the products are excellent. Moreover, the suggested catalyst was reusable for five runs with no significant decrease in catalytic activity.The palladium(II)-coordinated 5,10,15,20-tetrakis-(4-hexyloxyphenyl)-porphyrin as a macrocyclic palladium complex was covalently grafted to the surface of graphene oxide (denoted as GO-CPTMS@Pd-TKHPP). GO-CPTMS@Pd-TKHPP was characterized using microscopic and spectroscopic techniques for confirmation of functionalization. The synthesized catalyst was checked in the Suzuki-Miyaura and the Mizoroki-Heck coupling reactions. The catalyst is very easy to handle, environmentally safe and economical. Also, this catalytic system shows high catalytic activity and the yields of the products are excellent. Moreover, the suggested catalyst was reusable for five runs with no significant decrease in catalytic activity.
  PubDate: 2017-10-04T03:36:10.456586-05:
  DOI: 10.1002/aoc.4102
Efficient and recyclable novel Ni-based metal–organic framework
nanostructure as catalyst for the cascade reaction of alcohol
oxidation–Knoevenagel condensation
- Authors: Sima Aryanejad; Ghodsieh Bagherzade, Alireza Farrokhi
  Abstract: A novel Ni-based metal–organic framework (Ni-MOF) with a Schiff base ligand as an organic linker, Ni3(bdda)2(OAc)2⋅6H2O (H2bdda = 4,4′-[benzene-1,4-diylbis(methylylidenenitrilo)]dibenzoic acid), was synthesized and characterized using powder X-ray powder diffraction, thermogravimetric analysis, Brunauer–Emmett–Teller measurements, inductively coupled plasma atomic emission spectroscopy, transmission electron microscopy, elemental analysis and Fourier transform infrared spectroscopy. The synthesized Ni-MOF exhibited a high catalytic activity in benzyl alcohol oxidation using tert-butyl hydroperoxide under solvent-free conditions. Also, the efficiency of the catalyst was investigated in the cascade reaction of oxidation–Knoevanagel condensation under mild conditions. The Ni-MOF catalyst could be recovered and reused four times without significant reduction in its catalytic activity.A novel and well characterized nano Ni-MOF with a Schiff base ligand was prepared. The Ni-MOF has been applied as efficient catalyst in the cascade reaction of oxidation–Knoevanagel condensation under mild conditions.
  PubDate: 2017-10-04T03:26:00.503296-05:
  DOI: 10.1002/aoc.3995
New organotin supramolecular complexes based on copper cyanide and
auxiliary N-donor ligands as potent inhibitors of cancer cell lines: In
vitro and antioxidant experiments
- Authors: Safaa Eldin H. Etaiw; Safaa N. Abdou
  Abstract: The new synthesized supramolecular complexes (SC); [Cu2(CN)4(Et3Sn)2(tbpe)], 1 and [Cu2(CN)3(Et3Sn)(bpe)], 2 (tbpe = trans-1,2-bis(4-pyridyl)ethene and bpe = 1,2-bis(4-pyridyl)ethane), were characterized by elemental analyses, electrical conductance, spectroscopic studies and thermal analyses. UV–Vis spectra and magnetic moment data suggested the tetrahedral geometry around Cu(I) atoms. The structures of the SC 1 and 2 were also theoretically studied using molecular mechanics (MM+). The structures were minimized with a semi-empirical (PM3) method. The organotin compounds represent significant advances in the clinical management of some cancer cell lines. 1 and 2 were tested as inhibitors and their citotoxicities showed potent growth inhibitory activity for hepatocellular carcinoma HePG-2, mammary gland breast cancer MCF-7, human prostate cancer PC3 and Colorectal carcinoma HCT-116 cell lines. The tested compounds showed high inhibitory anti-oxidant activity either using erythrocyte hemolysis or ABTS method.Structures of the SC 1 (a) and 2 (b).New synthesized supramolecular complexes (SC); [Cu2(CN)4(Et3Sn)2(tbpe)], 1 and [Cu2(CN)3(Et3Sn)(bpe)], 2 have been synthesized and characterized structurally. The structures extend to form 3D- network via the (CN–Ete3Sn–CN) spacers and the tbpe or bpe ligand as connecting units as well as H-bonds. The structures of the SC 1 and 2 were also theoretically studied using molecular mechanics (MM+). 1 and 2 were tested as inhibitors and their citotoxicities showed potent growth inhibitory activity for different cell lines.
  PubDate: 2017-10-04T03:21:36.288537-05:
  DOI: 10.1002/aoc.4053
Synthesis, characterization and application of 3-methyl-1-sulfonic acid
imidazolium tetrachloroferrate as nanostructured catalyst for the tandem
reaction of β-naphthol with aromatic aldehydes and amide derivatives
- Authors: Ardeshir Khazaei; Ahmad Reza Moosavi-Zare, Saeed Firoozmand, Mohammad Reza Khodadadian
  Abstract: 3-methyl-1-sulfonic acid imidazolium tetrachloroferrate {[Msim]FeCl4} was prepared and fully characterized by fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX) and vibrating sample magnetometer (VSM) and used, as an efficient catalyst, for the tandem reaction of β-naphthol with aromatic aldehydes and benzamide at 110 °C under solvent-free conditions to give 1-amidoalkyl-2-naphthols in high yields and very short reaction times.3-methyl-1-sulfonic acid imidazolium tetrachloroferrate {[Msim]FeCl4} was used, as an efficient catalyst, for tandem reaction of β-naphthol with aromatic aldehydes and benzamide at 110 °C under solvent-free conditions.
  PubDate: 2017-10-04T03:16:01.588557-05:
  DOI: 10.1002/aoc.4058
Green and one-pot surface coating of iron oxide magnetic nanoparticles
with natural amino acids and biocompatibility investigation
- Authors: Hamed Nosrati; Marziyeh Salehiabar, Elahe Attari, Soodabeh Davaran, Hossein Danafar, Hamidreza Kheiri Manjili
  Abstract: We report the synthesis of iron oxide magnetic nanoparticles (IONPs) coated with various natural amino acids (AAs) using a one-pot reaction in an aqueous medium. Several AAs, which contained hydrophilic and hydrophobic groups, were selected to study their effects on size, morphology and toxicity of IONPs. Functionalized IONPs were characterized using X-ray diffraction, differential scanning calorimetry, thermogravimetric analysis, Fourier transform infrared spectroscopy, and scanning and transmission electron microscopies. Furthermore, vibrating sample magnetometry analysis shows these nanoparticles have excellent magnetic properties. Cellular toxicity of IONPs was also investigated on HFF2 cell lines. The AA-coated IONPs are non-toxic and biocompatible. Natural AA-coated IONPs show a potential for their development in in vitro and in vivo biomedical fields due to their non-toxicity, good ζ-potential and related small size and narrow size distribution.In this work we report the synthesis of IONPs coated with various AAs using a one-pot and in situ strategy. The AA-coated IONPs are non-toxic and biocompatible. Natural AA-coated IONPs show a potential for their development in in vitro and in vivo biomedical fields due to their non-toxicity, good ζ-potential and related small size and narrow size distribution.
  PubDate: 2017-09-29T11:21:30.900446-05:
  DOI: 10.1002/aoc.4069
2-hydroxyethylammonium formate ionic liquid grafted magnetic nanoparticle
as a novel heterogeneous catalyst for the synthesis of substituted
imidazoles
- Authors: Maryam Rajabzadeh; Hossein Eshghi, Reza Khalifeh, Mehdi Bakavoli
  Abstract: Catalytic one-pot condensation of benzil, aldehyde and ammonium acetate have been successfully carried out using 2-hydroxyethylammonium formate (HEAF) grafted on a magnetic nanoparticles as a new heterogeneous catalyst. The as-prepared catalyst was characterized by FT-IR, TEM, FESEM, VSM, TGA and XRD. This catalyst indicated significant advantages, such as excellent yields, shorter reaction time, reusability of the catalyst and easy workup process.1. Reusable nanocatalyst was prepared and characterized2. An efficient and mild method for the synthesis of substituted imidazoles
  PubDate: 2017-09-29T11:19:33.285629-05:
  DOI: 10.1002/aoc.4052
Synthesis and characterization of (pyrazolylethylphosphinite)nickel(II)
complexes and catalytic activity towards ethylene oligomerization
- Authors: Juliana M. Edor; Gershon Amenuvor, Collins Obuah, Alfred Muller, James Darkwa
  Abstract: Compounds (2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L1), 2-(3,5-di-tert-butyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L2), and 2-(3,5-diphenyl-1H-pyrazol-1-yl)ethyldiphenylphosphinite (L3) were prepared using the synthetic routes reported in literature. These compounds were reacted with [NiCl2(DME)2] or [NiBr2(DME)2] under appropriate reaction conditions to afford six new nickel(II) compounds ([NiCl2(L1)] (1), [NiCl2(L2)] (2), [NiCl2(L3)] (3), [NiBr2(L1)] (4), [NiBr2(L2)] (5) and [NiBr2(L3)] (6)). The new nickel(II) pre-catalysts catalyze the oligomerization of ethylene, in the presence of ethylaluminium dichloride as co-catalyst, to produce butenes, hexenes, octenes and higher carbon chain ethylene oligomers with very little Friedel-Crafts alkylation products when the reactions were run in toluene.Pyrazolylphosphinite nickel(II) pre-catalysts when activation with ethylaluminum dichloride in the presence of ethylene produce C4-C8 and higher carbon content oligomers.
  PubDate: 2017-09-29T11:19:02.973504-05:
  DOI: 10.1002/aoc.4101
The palladium-catalyzed C-N cross-coupling reaction of diheteroaryl
disulfides with heterocyclic amines
- Authors: Ming-Xia Liu; Zhang Zhang, Zheng-Jun Quan, Xi-Cun Wang
  Abstract: The Pd-catalyzed cross-coupling reaction of 1, 2-di(pyrimidin-2-yl) disulfides with heterocyclic amines including 2-amino pyrimidines and 1,3,4-thiadiazol-2-amines to deliver symmetrical C-N coupling products in moderate to good yields is reported. This method provides an opportunity for synthesis of bioactive molecules and pharmaceutically interesting compounds containing heterocycle motifs. The reported protocol shows good functional group compatibility, and provides a new strategy for preparation of C2-amination pyrimidine derivatives from heterocyclic disulfides.The Pd-catalyzed cross-coupling reaction of 1, 2-di(pyrimidin-2-yl) disulfides with heterocyclic amines including 2-amino pyrimidines and 1,3,4-thiadiazol-2-amines to deliver symmetrical C-N coupling products in moderate to good yields is reported. This method provides an opportunity for synthesis of bioactive molecules and pharmaceutically interesting compounds containing heterocycle motifs. The reported protocol shows good functional group compatibility, and provides a new strategy for preparation of C2-amination pyrimidine derivatives from heterocyclic disulfides.
  PubDate: 2017-09-29T11:18:54.246275-05:
  DOI: 10.1002/aoc.4020
Coordination compounds of some transition metal ions with new Schiff base
ligand derived from dibenzoyl methane. Structural characterization,
thermal behavior, molecular structure, antimicrobial, anticancer activity
and molecular docking studies
- Authors: Walaa H. Mahmoud; Gehad G. Mohamed, Omnia Y. El-Sayed
  Abstract: Series of Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Zn(II) and Cd(II) complexes were prepared with tetradentate Schiff base ligand derived by condensation of 2-aminophenol with dibenzoylmethane. The novel Schiff base H2L (2–2′-((1Z,1Z’)-(1,3-diphenyl propane-1,3 diylidene) bis (azanylylidene) diphenol) and its binary metal complexes were characterized by physicochemical procedures i.e. elemental analysis, FT-IR, UV–Vis, thermal analyses (TGA/DTG), mass spectrometry, magnetic susceptibility and conductometric measurements. On the basis of these studies, an octahedral geometry for all these complexes was proposed expect Ni(II) complex which had tetrahedral geometry. Molar conductivity values revealed that the complexes were electrolytes except Mn(II), Zn(II) and Cd(II) complexes were non electrolytes. The ligand bound to the metal ions via two azomethine N and two phenolic OH as indicated from the IR and 1H NMR spectral study. The molecular and electronic structures of H2L and its zinc complex were optimized theoretically and the quantum chemical parameters were calculated. The antimicrobial activity against a number of bacterial organisms as Streptococcus pneumonia, Bacillus Subtilis, Pseudomonas aeruginosa and Escherichia coli and fungi as Aspergillus fumigates, Syncephalastrum racemosum, Geotricum candidum and Candida albicans by disk diffusion method were screened for the Schiff base and its complexes. The Cd(II) complex has potent antimicrobial activity. Anticancer activity of the Schiff base ligand and its metal complexes were evaluated in human cancer (MCF-7 cells viability). The Cr(III) complex exhibited higher activity than other complexes and ligand. Molecular docking was used to predict the binding between Schiff base ligand (H2L) and its Zn(II) complex and the receptors of RNA of amikacin antibiotic (4P20) and human-DNA-Topo I complex (1SC7). The docking study provided useful structural information for inhibition studies.Novel Schiff base H2L and its binary metal complexes were characterized by standard physicochemical procedures.The molecular and electronic structures of H2L and its zinc(II) complex were optimized theoretically and the quantum chemical parameters were calculated.The Cd(II) complex has potent antimicrobial activity than the Schiff base and remaining complexes.The Cr(III) complex exhibited higher anticancer activity than other complexes and ligand.Molecular docking study provided useful structural information for inhibition studies.
  PubDate: 2017-09-29T11:18:24.402409-05:
  DOI: 10.1002/aoc.4051
Silver nanoparticles immobilized onto poly(4-vinylpyridine)-functionalized
magnetic nanoparticles: A robust magnetically recyclable catalyst for
oxidant-free alcohol dehydrogenation
- Authors: Ahmad Bayat; Mehdi Shakourian-Fard, Nazanin Talebloo, Mohammed Mahmoodi Hashemi
  Abstract: A heterogeneous and recyclable catalyst with a high loading of silver nanoparticles was synthesized via the silver nanoparticles being supported onto the surface of magnetic nanoparticles coated with poly(4-vinylpyridine). The synthesized catalyst was used in the dehydrogenation of alcohols to corresponding carbonyl compounds. A broad diversity of alcohols was converted into their corresponding carbonyl compounds in excellent yields. The catalyst was easily recovered by applying an external magnetic field and reused for seven reaction cycles without considerable loss of activity. The catalyst was fully characterized using various techniques.Oxidant-free dehydrogenation of alcohols was catalysed by silver nanoparticles immobilized onto poly(4-vinylpyridine)-functionalized magnetic nanoparticles.
  PubDate: 2017-09-29T11:17:23.041327-05:
  DOI: 10.1002/aoc.4061
A new air and moisture stable robust bio-polymer based palladium catalyst
for highly efficient synthesis of biaryl compounds
- Authors: Talat Baran; Nuray Yılmaz Baran, Ayfer Menteş
  Abstract: The designs of robust natural polymer based catalysts are important for catalytic systems in the view of industrial purposes and green chemistry. In this study, a new air and moisture stable robust starch-based Pd(II) catalyst was designed and characterized with different analytical techniques. Catalytic behavior of the prepared robust palladium(II) catalyst was investigated in the Suzuki coupling reactions of aryl iodides, aryl bromides and aryl chlorides with phenyl boronic acid under microwave irradiation using very short reaction time. Sustainability and reusability of the catalyst was also explored under benign conditions. As a result of the catalytic tests, the green catalyst gave excellent biphenyl yields, TONs and TOFs with very low catalyst loading. More importantly, the robust catalyst has showed that it can be reused several times without important loses from its activity in the coupling reactions. The study showed that the robust starch-based Pd(II) catalyst had more advantages than other catalysts reported in the literature due to its economic, sustainable, thermal durable, environmentally friendly and practice properties.Robust starch-based Pd(II) catalyst showed superior catalytic performanceThe catalyst indicated good mechanical and thermal durabilityHigh TON and TOF values were obtained; 49.500 and 495.000The catalyst exhibited an excellent reusability in Suzuki C-C reactions
  PubDate: 2017-09-29T11:16:04.690268-05:
  DOI: 10.1002/aoc.4076
Synthesis, characterization and biological application of cyclometalated
heteroleptic platinum(II) complexes
- Authors: Miral V. Lunagariya; Khyati P. Thakor, Nikita J. Patel, Mohan N. Patel
  Abstract: A series of square planar cyclometalated heteroleptic platinum(II) complexes of the type [(C^N)Pt(O^O)] [where, O^O is a β-diketonato ligand of acetylacetone (acac), C^N = cyclometalating 7-(4-fluorophenyl)-5-phenylpyrazolo[1,5-a]pyrimidine (L1), 7-(4-chlorophenyl)-5-phenylpyrazolo[1,5-a]pyrimidine (L2), 7-(4-bromophenyl)-5-phenylpyrazolo[1,5-a]pyrimidine (L3), 7-(4-methoxyphenyl)-5-phenylpyrazolo[1,5-a]pyrimidine (L4), 5-phenyl-7-(p-tolyl)pyrazolo[1,5-a]pyrimidine (L5)] have been design, synthesized and characterized. All compounds have been screened for biological studies like in vitro antibacterial, in vitro cytotoxicity, cellular level cytotoxicity, absorption titration, viscosity measurements, fluorescence quenching analysis, molecular docking and DNA nuclease. The intrinsic binding constants (Kb) of compounds with HS-DNA has been obtained in range of 2.892–0.242 × 105 M−1. All the compounds bound with HS DNA by partial intercalative mode of binding. MIC study has been carried out against Gram(+ve) and Gram(−ve) bacterial species. In vitro cytotoxicity against brine shrimp lethality bioassay has been also carried out. The LC50 values of the ligands and complexes have been found in range of 56.49–120.22 μg/mL and 6.71–11.96 μg/mL, respectively.Synthesis of organometallic Pt(II) complexes with heterocyclic pyrazolo[1,5-a]pyrimidine derivatives bidentate C, N –donor ligands. Characterizationof the compounds was carried out by elemental analysis (C, H, N, S), 1H NMR, 13C NMR, FT-IR, UV–visible, molar conductivity, mass spectroscopic and TGA spectroscopy. Accommodation of the organometallic Pt(II) complexes in the DNA base pairs as an partial intercalative mode of binding have been confirmed through molecular docking, absorption titration analysis, viscosity measurements and fluorescence quenching analysis. DNA cleavage assay was carried out by gel electrophoresis technique. All the heterocyclic compounds like, pyrazolo[1,5-a]pyrimidine based ligands, cisplatin, transplatin and their cyclometalated Pt(II) complexes have been examined for in vitro antibacterial assay, in vitro cellular level cytotoxicity against S. Pombe cells, and in vitro cytotoxicity against brine shrimp lethality bioassay (LC50).
  PubDate: 2017-09-28T06:11:31.164362-05:
  DOI: 10.1002/aoc.4045
Phthalhydrazide nanoparticles as new highly reusable organic photocatalyst
in the photodegradation of organic and inorganic contaminants
- Authors: Roya Mohammadzadeh Kakhki; Reza Tayebee, Sara Hedayat
  Abstract: Phthalhydrazide nanoparticles are introduced as a new, efficient, stable and reusable organic photocatalyst for the photodegradation of a range of azo dyes, including methyl orange, methyl red, congo red and yellow titan, 4-nitrophenol and permanganate as important organic and inorganic contaminants. Various experimental parameters including pH, photocatalyst dose, dye concentration and illumination time were investigated for methyl orange as a model substrate. The results revealed high degradation efficacy, up to 93.6%, for methyl orange in 20 min. Moreover, a preliminary kinetic study along with a proposed photodegradation mechanism is included in this study. Mechanistic investigations showed that phthalhydrazide behaved as a photoreduction catalyst. With the addition of Cl− ion, as a hole scavenger, photodegradation efficacy for methyl orange was improved. Results showed that phthalhydrazide nanoparticles behaved better than commercial bulk phthalhydrazide and both performed as successful photocatalysts for photoreduction of the mentioned organic and inorganic compounds.Phthalhydrazide was investigated as a new, efficient, stable and reusable organic photocatalyst for the photodegradation/photoreduction of a range of important organic and inorganic oxidizing contaminants.
  PubDate: 2017-09-25T06:22:09.160976-05:
  DOI: 10.1002/aoc.4033
Catalytic activity of Fe(II) and Cu(II) PNP pincer complexes for Suzuki
coupling reaction
- Authors: Lolakshi Mahesh Kumar; Rasheeda M. Ansari, Badekai Ramachandra Bhat
  Abstract: Iron and copper PNP pincer complexes of the type [Fe(L)SO4] and [Cu(L)OCOCH3] are reported and represented as C-1 and C-2 catalyst. Both the complexes were synthesized using bis(diphenylphosphino)pyridine-2,6-diamine [L], and salts of ‘Fe’ and ‘Cu’ by direct coordination method. The as synthesized complexes were characterized using FTIR, UV–Vis, mass analysis and TGA. The effect of reaction time, catalyst load, solvent and base on the reaction between phenylboronic acid and para substituted bromobenzenes in the presence of the catalysts were investigated for evaluating the catalytic efficiency of the complexes. The results obtained highlight the enhanced C-C coupling reactions with the use of 0.4 mol% of the catalyst C-1 in 14 h and 0.6 mol% of C-2 in 16 h respectively with Cs2CO3 base and ACN as solvent media. Of the two complexes reported, C-1 with iron as catalytically active metal is more stable and active towards coupling which is reflected in its better coupling yields in lesser reaction time compared to copper bearing C-2 complex.The study of iron and copper PNP pincer complexes of the type [Fe(L)SO4] (C-1) and [Cu(L)OCOCH3] (C-2) are reported for their catalytic application in Suzuki coupling reaction. The reaction between phenylboronic acid and para substituted bromobenzenes in the presence of the prepared catalysts were used as model reaction for evaluating the catalytic performance in terms of reaction time, catalyst load, and solvent and base effect. The obtained results indicate the enhanced C-C coupling with C-1 being better of the two.
  PubDate: 2017-09-25T06:21:46.817475-05:
  DOI: 10.1002/aoc.4054
Click functionalization of magnetite nanoparticles: A new magnetically
recoverable catalyst for the selective epoxidation of olefins
- Authors: Majid Masteri-Farahani; Samaneh Shahsavarifar
  Abstract: A new magnetically recoverable heterogeneous molybdenum catalyst was developed by means of a click chemistry approach. First, silica-coated magnetite nanoparticles were functionalized using a bidentate ligand via thiol–ene click reaction of mercaptopropyl-modified magnetite nanoparticles with acrylic acid. Then, a molybdenum complex was covalently supported on the surface of the clicked silica-coated magnetite nanoparticles. The prepared catalyst was characterized using Fourier transform infrared and inductively coupled plasma optical emission spectroscopies, X-ray diffraction, vibrating sample magnetometry and transmission electron microscopy. The catalytic performance of the prepared heterogeneous catalyst was investigated in the epoxidation of olefins with tert-butyl hydroperoxide as oxidant. This catalyst could be reused for five runs without significant loss of activity and selectivity.A new magnetically recoverable heterogeneous molybdenum catalyst was developed by means of a click chemistry approach. The catalytic performance of the prepared heterogeneous catalyst was investigated in the epoxidation of olefins with tert-butyl hydroperoxide as oxidant. This catalyst could be reused for five runs without significant loss of activity and selectivity.
  PubDate: 2017-09-25T06:21:01.351553-05:
  DOI: 10.1002/aoc.4064
A novel and highly efficient polyaniline-functionalized multiwall carbon
nanotube-supported cu(I) complex for Sonogashira coupling reactions of
aryl halides with phenylacetylene
- Authors: Abdol R. Hajipour; Saeideh Jajarmi
  Abstract: A polyaniline-functionalized multiwall carbon nanotube-supported Cu(I) complex was developed as an efficient catalyst for the Sonogashira reactions of aryl halides with phenylacetylene in the presence of potassium hydroxide in dimethylformamide at 135 °C under nitrogen atmosphere. The corresponding products were generated in good to excellent yields using this catalytic system. Moreover, the multiwall carbon nanotube-supported Cu(I) catalyst was simply recycled and reused for six consecutive runs.An efficient and inexpensive copper nanocatalyst was synthesized for Sonogashira coupling reactions of aryl halides with phenylacetylene, and was simply recycled and reused for six consecutive runs.
  PubDate: 2017-09-25T06:15:46.433268-05:
  DOI: 10.1002/aoc.3992
Application of artificial neural network for comparison and modeling of
the ultrasonic and stirrer assisted removal of anionic dye using activated
carbon supported with nanostructure material
- Authors: Abdol Mohammad Ghaedi; Parisa Karami, Mehrorang Ghaedi, Azam Vafaei, Ebrahim Alipanahpour Dil, Fatemeh Mehrabi
  Abstract: In this study, a green approach has been described for the synthesis of copper sulfide nanoparticles loaded on activated carbon (CuS-NP-AC) and usability of it for the removal of sunset yellow (SY) dye by ultrasound-assisted and stirrer has been compared. In addition, the artificial neural network (ANN) model has been employed for a forecasting removal percentage of SY dye using the results obtained. This material was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The impact of variables, including initial dye concentration (mg/L), pH, adsorbent dosage (g), sonication time (min) and temperature (°C) on SY removal was studied. Fitting the experimental equilibrium data of different isotherm models such as Langmuir, Freundlich, Temkin and Dubinin–Radushkevich models display the suitability and applicability of the Langmuir model. Analysis of experimental adsorption data of different kinetic models including pseudo-first and second order, Elovich and intraparticle diffusion models indicate the applicability of the second-order equation model. The adsorbent (0.005 g) is applicable for successful removal of SY dye (> 98%) in short time (9 min) under ultrasound condition. A three layer ANN models with 8 and 6 neurons at hidden layer was selected as optimal models using stirrer and ultrasonic, respectively. These models displayed a good agreement between forecasted data and experimental data with the determination coefficient (R2) of 0.9948 and 0.9907 and mean squared error (MSE) of 0.0001 and 0.0002 for training set using stirrer and ultrasonic, respectively.CuS-NP-AC was synthesized and usability of it for the removal of sunset yellow dye by ultrasound-assisted and stirrer has been compared. In addition, the artificial neural network model has been employed for a forecasting removal percentage of sunset yellow dye using the results obtained. For testing data set, the optimal ANN models showed a good agreement between forecasted data and experimental data. The data display that the adsorption process follow the pseudo-second-order kinetic and Langmuir isotherm.
  PubDate: 2017-09-25T06:11:57.166016-05:
  DOI: 10.1002/aoc.4050
Phosphine (oxide)-(thio) phenolate palladium complexes: Synthesis,
characterization and (co)polymerization of norbornene
- Authors: Yanping Zhang; Hongliang Mu, Yanguo Li, Yuesheng Li
  Abstract: A series of palladium complexes (2a–2g) (2a: [6-tBu-2-PPh2-C6H3O]PdMe(Py); 2b: [6-C6F5–2-PPh2-C6H3O]PdMe(Py); 2c: [6-tBu-2-PPhtBu-C6H3O]PdMe(Py); 2d: [2-PPhtBu-C6H4O] PdMe(Py); 2e: [6-SiMe3–2-PPh2-C6H3O]PdMe(Py); 2f: [2-tBu-6-(Ph2P=O)-C6H3O]PdMe(Py); 2g: [6-SiMe3–2-(Ph2P=O)-C6H3S]PdMe(Py)) bearing phosphine (oxide)-(thio) phenolate ligand have been efficiently synthesized and characterized. The solid-state structures of complexes 2d, 2f and 2g have been further confirmed by single-crystal X-ray diffraction, which revealed a square-planar geometry of palladium center. In the presence of B(C6F5)3, these complexes can be used as catalysts to polymerize norbornene (NB) with relatively high yields, producing vinyl-addition polymers. Interestingly, 2a/B(C6F5)3 system catalyzed the polymerization of NB in living polymerization manner at high temperature (polydispersity index 1.07, Mn up to 1.5 × 104). The co-polymerization of NB and polar monomers was also studied using catalysts 2a and 2f. All the obtained co-polymers could dissolve in common solvent.Several novel palladium complexes based on phosphine (oxide)-(thio) phenolate ligand were synthesized and characterized. All the palladium complexes exhibited a square-planar geometry of palladium center with pyridine located trans to the phosphorus atom. They can used as catalysts to (co)polymerize norbornene and polar norbornene derivatives with relatively high yields in the presence of B(C6F5)3. Interestingly, the polymerization of norbornene was initiated in a living polymerization manner by complex 3a/B(C6F5)3 system at high temperature (polydispersity index (PDI): 1.07, Mn up to 1.5 × 104).
  PubDate: 2017-09-25T06:10:42.334231-05:
  DOI: 10.1002/aoc.4013
The effect of synthesis procedure on the catalytic performance of
isostructural ZIF-8
- Authors: Bibimaryam Mousavi; Somboon Chaemchuen, Chizoba I. Ezugwu, Ye Yuan, Francis Verpoort
  Abstract: We demonstrate the synthesis of isostructural zeolitic imidazole framework (ZIF-8) using four distinct synthetic methods. Subsequently, the variations in physicochemical properties were analyzed through the catalytic reaction of CO2 cycloaddition of epoxide. It was thus demonstrated that simply by changing the type of synthetic method for the preparation of ZIF-8, the physicochemical properties were changed significantly which in turn influenced the catalytic activity of ZIF-8. It was found that the synthetic method affected the crystal growth and consequently influenced the physicochemical properties which are crucial aspects in metal–organic framework applications. There is an almost exponential relationship between the reactivity of various ZIF-8 samples in CO2 cycloaddition of epoxide and the surface area, CO2 adsorption and pore volume.ZIF-8 was synthesized using different methods including a new spray-drying method. It was shown that although they showed the same XRD patterns, their physicochemical properties were changed due to variation in time of crystallization. There is an almost exponential relationship between the reactivity of different ZIF-8 samples in CO2 cycloaddition of epoxide with surface area, CO2 adsorption and pore volume.
  PubDate: 2017-09-25T06:06:21.728704-05:
  DOI: 10.1002/aoc.4062
Green synthesis of silver nanoparticles using water extract of Salvia
leriifolia: Antibacterial studies and applications as catalysts in the
electrochemical detection of nitrite
- Authors: Mehdi Baghayeri; Behnam Mahdavi, Zahra Hosseinpor-Mohsen Abadi, Samaneh Farhadi
  Abstract: Here, a green method is described for the biosynthesis of Ag nanoparticles (Ag NPs) using aqueous extracts of the leaf of Salvia leriifolia as reducing and stabilizing agent. Various techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM) and X-ray diffraction (XRD) were employed for the characterization of the structure and morphology of bio-synthesized AgNPs. The results reveal that AgNPs synthesized with uniform spherical morphology and average diameters of 27 nm. The AgNPs as a green and efficient heterogeneous catalyst presented superior antibacterial activity. Direct electrochemistry studies of the synthesized AgNPs confirmed that nanoparticles retained their direct electrochemical activity. This is mainly attributed to the proper biosynthesis process, the large specific surface area and the good conductivity of the synthesized nanoparticles. Hence, the present synthesized AgNPs displayed good electrocatalytic activity to the reduction of nitrite ions. The proposed method is highly recommended as a novel platform for the development of electrochemical sensors which can further expand the applications of AgNPs. Antibacterial activity of the synthesized AgNPs was evaluated against nine microorganisms. AgNPs prevented the growth of all selected bacteria. The nanoparticles inhibited the growth of Pseudomonas aeruginosa, Klebsiella pneumonia, Staphylococcus coagulase, Acinetobacter baumannii, and Streptococcus pneumonia more than antibiotic of vancomycin, however, the ability of AgNPs against Echerishia coli and Serratia marcescens was less than the antibiotic. On the other hand AgNPs were active against Citrobacter frurdii, while the antibiotic was inactive.Silver nanoparticles have been synthesized and characterized by a green method. The antibacterial activity of the AgNPs in was investigated. These nanoparticles exhibited high electrocatalytic activities in the direct reduction of nitrite at a simple electrochemical sensor.
  PubDate: 2017-09-25T06:06:13.40701-05:0
  DOI: 10.1002/aoc.4057
MgBr2 supported on Fe3O4@SiO2 ~ urea nanoparticle: An efficient catalyst
for ortho-formylation of phenols and oxidation of benzylic alcohols
- Authors: Ebrahim Soleimani; Nadieh Yaesoobi, Hamid Reza Ghasempour
  Abstract: Urea was successfully immobilized on the surface of chloropropyl-modified Fe3O4@SiO2 core–shell magnetic nanoparticles, then supported by MgBr2 and acts as a unique catalyst for oxidation of benzylic alcohols to aldehydes and ketones, and ortho-formylation of phenols to salicylaldehydes. The prepared catalyst was characterized by FT-IR, transmission electron microscopy, scanning electron microscopy, X-ray powder diffraction, dispersive X-ray spectroscopy, CHN and TGA. It was found that Fe3O4@SiO2 ~ urea/MgBr2 showed higher catalytic activity than homogenous MgBr2, and could be reused several times without significant loss of activity.MgBr2 was successfully attached on the surface of Fe3O4@SiO2-Urea nanoparticles, then this catalyst was used as a unique catalyst for oxidation of benzylic alcohols to aldehydes and ketones, and ortho-formylation of phenols to salicylaldehydes. This new heterogenous catalyst showed higher catalytic activity than homogenous MgBr2.
  PubDate: 2017-09-25T06:05:37.942389-05:
  DOI: 10.1002/aoc.4006
Polymer complexes. LXVIII. Spectroscopic studies of supramolecular
copper(II) polymeric complexes of biologically active monomer derived from
novel sulfa drug
- Authors: A.Z. El-Sonbati; M.A. Diab, Sh.M. Morgan, M.Z. Balboula
  Abstract: The novel ligand N-[4-(5-methylisoxazol-3-ylsulfamoyl)phenyl]acrylamide (HL) was prepared via amidation of 4-amino-N-(5-methylisoxazol-3-yl)benzenesulfonamide with acryloyl chloride in benzene as solvent. Polymeric complexes with HL were prepared and characterized using elemental analysis, spectral studies (infrared, mass, UV–visible and electron paramagnetic resonance), powder X-ray diffraction, thermal analysis, molar conductivity and magnetic susceptibility. Infrared spectral studies reveal that HL behaves as a neutral bidentate ligand. Powder X-ray diffraction patterns of HL and polymer complexes show many diffraction peaks which indicate polycrystalline phases. Based on magnetic moment and solid reflectance measurements, the polymer complexes have square planar and octahedral geometries. Molecular docking was used to predict the binding between HL and the receptors of 3hb5-oxidoreductase (breast cancer) and 2q7k-hormone (prostate cancer).The ESR technique is a very sensitive tool for obtaining the information on the chemical environments and the coordination states of Cu2+. The ESR parameters were used to evaluate the bonding parameters which may be regarded as measures of covalency of the in-plane σ-bonding, in-plane Π-bonding and out of plane Π-bonding, respectively. The ESR data showed that the value of α2 increases with increasing gav. and A . Our results are in agreement with the respective positions of the anions as given in the spectrochemical series.
  PubDate: 2017-09-25T06:01:59.993841-05:
  DOI: 10.1002/aoc.4059
Application of chromium-doped fullerene as a carrier for thymine and
uracil nucleotides: Comprehensive density functional theory calculations
- Authors: Ali Shokuhi Rad; Sadegh Mehdi Aghaei, Elaheh Aali, Majid Peyravi, Mohsen Jahanshahi
  Abstract: The interactions of the nucleobases thymine (C5H6N2O2) and uracil (C4H4N2O2) with Cr-doped C20 fullerene (C19Cr) are investigated by performing density functional theory calculations. The adsorption of these nucleobases on C19Cr leads to two distinct geometries (P1 and P2) differing in the orientation of the nucleobases. The interaction of the nucleobases with the C19Cr nanocluster is highly exothermic, revealing that they are chemically adsorbed on C19Cr. The results show that the binding energy of the thymine–C19Cr complex is slightly higher than that of the uracil–C19Cr complex. In addition, the P2 geometry is more stable compared to P1 due to the higher binding energy in the former configuration. However, based on the results of natural bond orbital and frontier molecular orbitals analyses, the C19Cr nanocage has higher reactivity with the nucleobases in P1 geometry in comparison with P2 due to the larger charge transfer and orbital hybridization in the former geometry. Moreover, the band gap of the C19Cr nanocage decreases after interaction with the nucleobases, and interestingly the impact is more pronounced for P1 geometry, confirming the higher sensitivity of C19Cr to the nucleobases in P1 geometry. Our findings reveal the promising potential of C19Cr as an organometallic carrier for nucleobases thymine and uracil.The interaction between nucleobases thymine and uracil with C19Cr nanocage was studied.Both nucleobases can be adsorbed on the Cr-fullerene complex in two distinct geometries.The high binding energies of the nucleobase-C19Cr complexes are indicative of chemisorption.The C19Cr showed a slightly better sensitivity to thymine in comparison with uracil nucleobase.The energy gap of C19Cr nanocage drops after complexation with nucleobases.
  PubDate: 2017-09-25T06:00:37.316793-05:
  DOI: 10.1002/aoc.4070
Catalytic reactivity of new Ni(II), cu(II) and Sn(II) complexes for
decolorization of indigo carmine in aqueous solution, high efficiency of
copper complex
- Authors: Amr Mohammad Nassar
  Abstract: A new Ni(II), Cu(II) and Sn(II) Schiff base complexes were synthesized in this work. The characterization of the new complexes is carried out by elemental analysis, FT-IR, UV–Visible, 1H NMR and 13C NMR spectroscopy, conductance analysis, magnetic measurements and thermal gravimetric analysis. It was found that the ligand behaves as a dibasic bidentate which coordinated to the metal center through two deprotonated hydroxyl groups to form tetrahedral complex with Ni(II) and octahedral complex with Cu(II). The ligand acts as neutral bidentate through azomethine nitrogen and thiazol sulfur to form octahedral complex with Sn(II). The synthesized complexes are evaluated as catalysts for oxidative degradation of indigo carmine dye using H2O2 as oxidant and the efficiency of the catalysts is determined. The copper complex shows the best catalytic action with efficiency 92.17% after 25 min.1-New metal complexes of nickel, copper and tin are synthesized and characterized by physicochemical techniques in the present work.2-The catalytic activity of the complexes are evaluated for degradation of indigo carmine dye.3-The copper complex exhibits the higher catalytic activity with efficiency 92.17% for dye degradation.
  PubDate: 2017-09-25T05:55:55.593489-05:
  DOI: 10.1002/aoc.4056
Use of metal composite MOF-5-Ag2O-NPs as an adsorbent for the removal of
Auramine O dye under ultrasound energy conditions
- Authors: Seyed Amin Hosseinpour; Gholamreza Karimipour, Mehrorang Ghaedi, Kheibar Dashtian
  Abstract: In this work, MOF-5 composited with Ag2O nanoparticles was prepared and characterized via X-ray diffraction, field emission-scanning electron microscopy, energy-dispersive spectroscopy and FT-IR analysis. This new material was subsequently employed for removing basic yellow dye [Auramine O (AO)] from aqueous solution under ultrasound irradiation. Several experiments were designed by central composite design in which operational parameters such as such as pH, MOF-5-Ag2O mass and initial concentration of AO involved in the process were optimized. The significance of individual parameters and their possible interactions were investigated using analysis of variance (anova). The optimum values of 6, 0.025 g and 6 mg l−1 were obtained for the pH, MOF-5-Ag2O-NPs mass and the initial concentrations of AO, respectively, with desirability of 1.0. At such conditions, the efficiency for the removal of AO was found to be 89.45%. Various isotherm models for fitting the experimental equilibrium data were studied, and it was found that the Langmuir model has the highest efficiency for correlation of experimental equilibrium data, so that the monolayer adsorption capacity of MOF-5-Ag2O for successful removal of AO was 260.70 mg g−1 at optimal conditions.In this work, MOF-5-Ag2O nanocomposite was prepared and applied for enhanced removing of Auramine O dye from aqueous solution under ultrasound irradiation.
  PubDate: 2017-09-25T05:50:55.251132-05:
  DOI: 10.1002/aoc.4007
Iron(III) porphyrin catalyzed ionic liquid mediated polymerization of
methylmethacrylate
- Authors: Anchal Singhal; Sohail Ahmad, Shive M.S. Chauhan
  Abstract: A novel application of iron(III)porphyrin catalyst, 5,10,15,20 − tetrakis − (2′,6′-dichlorophenyl)porphyrinatoiron(III) chloride is reported for the reaction of methyl methacrylate with hydrogen peroxide in imidazolium ionic liquids at ambient temperature. The reaction furnished polymethyl methacrylate in 75–94% yields. The yield of the polymer was optimized upon changing the reaction media, ratio of catalyst, oxidant and substrate, reaction time and quenchers. The polymethyl methacrylate was secured as highly stereoregular with predominantly syndiotactic sequences as analyzed with the aid of NMR (1H and 13C) and infrared spectroscopy. Besides, the number-average molecular weights (Mn) were attained in the range of 15,000 to 55,000 with narrow polydispersity (~1.1–1.9) as calculated using gel permeable chromatography (GPC).A new application of iron(III)porphyrin, Cl8TPPFe(III)Cl is advocated for the polymerization of methyl methacrylate in the presence of hydrogen peroxide using ionic liquids as reaction medium at ambient temperature. The reaction afforded highly stereoregular poly(methyl methacrylate) with syndiotactic predominance in good to excellent yields as analyzed using NMR (1H and 13C) and infrared spectroscopy. The number-average molecular weights (Mn) were attained in the range of 15,000-55,000 with narrow polydispersity (~1.1-1.9) as calculated using gel permeable chromatography.
  PubDate: 2017-09-25T05:50:40.088265-05:
  DOI: 10.1002/aoc.4044
Issue Information
- Abstract: No abstract is available for this article.
  PubDate: 2017-09-20T04:04:08.849282-05:
  DOI: 10.1002/aoc.3621
Cover Image
- Authors: Savita Beniwal; Sunil Chhimpa, Deepti Gaur, P.J. John, Yashpal Singh, Jyoti Sharma
  Abstract: The cover image, by Savita Beniwal et al., is based on the Full Paper Syntheses, characterization, antibacterial activity and molecular modelling of phenylantimony(III) heteroleptic derivatives containing substituted oximes and piperidine dithiocarbamate,
  DOI : 10.1002/aoc.3725.
  PubDate: 2017-09-20T04:04:03.015842-05:
Some divalent metal(II) complexes of novel potentially tetradentate Schiff
base N,N′-bis(2-carboxyphenylimine)-2,5-thiophenedicarboxaldhyde:
Synthesis, spectroscopic characterization and bioactivities
- Authors: Ayman A. Abdel Aziz; Ibrahim S.A. El-Sayed, Mostafa M.H. Khalil
  Abstract: A novel tetradentate dianionic Schiff base ligand, N,N′-bis(2-carboxyphenylimine)-2,5-thiophenedicarboxaldhyde (H2L) and some first row d-transition metal chelates (Co(II), Cu(II), Ni(II) and Zn(II)) were synthesized and characterized using various physicochemical and spectroscopic methods. The spectroscopic data suggested that the parent Schiff base ligand coordinates through both deprotonated carboxylic oxygen and imine nitrogen atoms. The free Schiff base and its metal chelates were screened for their antimicrobial activities for various pathogenic bacteria and fungi using the agar well diffusion method. The antibacterial and antifungal activities of all the newly synthesized compounds are significant compared to the standard drugs ciprofloxacin and nystatin. The antioxidant activities of the compounds were determined by reduction of 1,1-diphenyl-2-picrylhydrazyl and compared with that of vitamin C as a standard. DNA binding ability of the novel Schiff base and its complexes was investigated using absorption spectroscopy, fluorescence spectroscopy, viscosity measurements and thermal denaturation. The obtained results clearly demonstrate that the binding affinity with calf thymus DNA follows the order: Cu(II) complex > Ni(II) complex > Zn(II) complex > Co(II) complex >H2L. Furthermore, the DNA cleavage activity of the newly synthesized ligand and its metal complexes was investigated using supercoiled plasmid DNA (pUC18) gel electrophoresis.Novel mononuclear, four coordinated Co(II), Ni(II), Cu(II) and Zn(II) complexes were synthesized via thermal reaction of their metal acetate salts with the novel tetradentate Schiff base N,N′-(1-carboxyphenylimine)-2,5-thiophenedicarboxaldhyde. Investigation of antioxidation properties, binding with calf thymus DNA and DNA cleavage properties of the novel compounds suggested possible utilization of novel compounds for pharmaceutical applications.
  PubDate: 2017-03-27T04:37:15.079758-05:
  DOI: 10.1002/aoc.3730
Density functional theory/B3LYP study of nanometric
4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide
complexes: Quantitative structure–activity relationship, docking,
spectral and biological investigations
- Authors: Fawaz A. Saad; Marwa G. Elghalban, Nashwa M. El-Metwaly, Hoda El-Ghamry, Abdalla M. Khedr
  Abstract: New metal ion complexes were isolated after coupling with 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (H2L) drug ligand. The structural and molecular formulae of drug derivative and its complexes were elucidated using spectral, analytical and theoretical tools. Vibrational spectral data proved that H2L behaves as a monobasic bidentate ligand through one nitrogen from azo group and ionized hydroxyl oxygen towards all metal ions. UV–visible and magnetic moment measurements indicated that Fe(III), Cr(III), Mn(II) and Ni(II) complexes have octahedral configuration whereas Cd(II), Zn(II) and Co(II) complexes are in tetrahedral form. The Cu(II)complex has square planar geometry as verified through electron spin resonance essential parameters. X-ray diffraction data indicated the amorphous nature of all compounds with no regular arrangement for the solid constituents during the precipitation process. Transmission electron microscopy images showed homogeneous metal ion distribution on the surface of the complexes with nanometric particles. Coats–Redfern equations were applied for calculating thermo-kinetic parameters for suitable thermal decomposition stages. Gaussian09 and quantitative structure–activity relationship modelling studies were used to verify the structural and biological features. Docking study using microorganism protein receptors was implemented to throw light on the biological behaviour of the proposed drug. The investigated ligand and metal complexes were screened for their in vitro antimicrobial activities against fungal and bacterial strains. The resulting data indicated that the investigated compounds are highly promising bactericides and fungicides. The antitumour activities of all compounds were evaluated towards human liver carcinoma (HEPG2) cell line.Optimized structure of 4-(2,4-dihydroxy-5-formylphen-1-ylazo)-N-(4-methylpyrimidin-2-yl)benzenesulfonamide (H2L)
  PubDate: 2017-03-20T02:36:30.985366-05:
  DOI: 10.1002/aoc.3721
Synthesis, characterization and biological activities of two novel
orthopalladated complexes: Interactions with DNA and bovine serum albumin,
antitumour activity and molecular docking studies
- Authors: Kazem Karami; Sara Hashemi, Janusz Lipkowski, Fatemeh Mardani, Amir Abbas Momtazi-borojeni, Zohreh Mehri Lighvan
  Abstract: [Pd(L1)(C,N)]CF3SO3 and [Pd(L2)(C,N)]CF3SO3 (L1 = 2,2′-bipyridine, L2 = 1,10-phenanthroline and C,N = benzylamine) novel orthopalladated complexes have been synthesized and characterized using various techniques. The binding of the complexes with native calf thymus DNA (CT-DNA) was monitored using UV–visible absorption spectrophotometry, fluorescence spectroscopy and thermal denaturation studies. Our results indicate that these complexes can strongly bind to CT-DNA via partial intercalative mode. In addition, fluorescence spectrometry of bovine serum albumin (BSA) with the complexes shows that the fluorescence quenching mechanism of BSA is a static process. The results of site-competitive replacement experiments with specific site markers clearly indicate that the complexes bind to site I of BSA. Notably, the complexes exhibit significant in vitro cytotoxicity against two human cancer cell lines (Jurkat and MCF-7) with IC50 values varying from 37 to 53 μM. Finally, a molecular docking experiment effectively proves the binding of the Pd(II) complexes to DNA and BSA.Two new orthopalladated complexes have been synthesized and characterized by various techniques. The compounds can bind to CT-DNA via partial intercalative mode. Fluorescence spectrometry of BSA with the complexes shows that the fluorescence quenching mechanism of BSA is a static process. The complexes exhibit significant in vitro cytotoxicity against two human cancer cell lines (Jurkat and MCF-7). A molecular docking experiment effectively proves the binding of the Pd(II) complexes to DNA and BSA.
  PubDate: 2017-03-20T02:26:15.190949-05:
  DOI: 10.1002/aoc.3740
Water-soluble Schiff base Cu(II) and Zn(II) complexes: Synthesis, DNA
targeting ability and chemotherapeutic potential of Cu(II) complex for
hepatocellular carcinoma – in vitro and in vivo approach
- Authors: Narayanaperumal Pravin; Ganesan Kumaravel, Raju Senthilkumar, Natarajan Raman
  Abstract: Reliable compounds with low toxicity are tempting potential chemotherapeutics. With an aim of achieving less toxic but more potent metallodrugs, four new-generation hydrophilic Cu(II) and Zn(II) complexes with DNA-targeting properties were synthesized and characterized using various physicochemical data. The excellent DNA binding and cleavage results confirmed the mode of binding of DNA with the complexes and their ability to denature it. The profound in vitro cytotoxicity exhibited by complex 3 against a panel of cell lines (HeLa, MCF-7 and HepG-2) along with NHDF (normal human dermal fibroblasts) with distinct activity towards HepG-2 and low toxicity to NHDF prompted in vivo studies of induced hepatocellular carcinoma-affected Swiss albino rats. On evaluating various serum hepatic, biological and histopathological parameters, complex 3 showed excellent activity in restoring the damaged liver to normal. As a means of identifying the pathway of DNA damage, flow cytometric evaluation of cell cycle analysis was performed, which revealed S phase arrest-induced apoptosis in HepG-2 cells by complex 3, making it a cell cycle-specific drug.Reliable compounds with low toxicity are tempting potential chemotherapeutics. To achieve less toxic but more potent metallodrugs, four new hydrophilic Cu(II) and Zn(II) complexes with DNA-targeting properties were synthesized and characterized. The binding and cleavage results confirmed the mode of binding of DNA with the complexes and their ability to denature it.
  PubDate: 2017-02-22T06:11:00.679759-05:
  DOI: 10.1002/aoc.3739
Synthesis of retinoid analogues of juvenile hormones
- Authors: Lotfi Doumandji; Hubert Matondo, Sébastien Estaran, Boudjema Hamada, Christophe Lagneau, James Devillers, André Yébakima, Annick Doucet-Panaye, Jean-Pierre Doucet, Armand Lattes
  Abstract: As part of a collaborative research project aimed at designing new chemicals active on mosquito larvae, we sought accessible raw materials and an efficient synthesis method for preparing large amounts of active substances. For this we selected retinoic acid, which has functionality close to that of juvenile hormones. From this molecule we developed ester and trifluoromethyl ketone synthesis that was fast and led to good yields.The synthesis of the target molecule was conducted using a two-step procedure. Firstly, the corresponding acyl chloride was prepared by reacting trans-retinoic acid with thionyl chloride in anhydrous dichloromethane in the presence of pyridine as catalyst. The second step was a trifluoromethylation the acyl chloride with trifluoromethylcopper, which showed better responsiveness.
  PubDate: 2017-02-20T01:20:29.806862-05:
  DOI: 10.1002/aoc.3736
Synthesis and characterization of iron- and nitrogen-functionalized
graphene catalysts for oxygen reduction reaction
- Authors: Rapidah Othman; Md. Sohrab Hossain, Noor H. Jabarullah
  Abstract: Iron- and nitrogen-functionalized graphene (Fe-N-G), as well as iron- and nitrogen-functionalized oxidized graphene (Fe-N-Gox) catalysts were synthesized as non-noble metal electrocatalysts for oxygen reduction reaction (ORR). The physical properties of the resultant catalysts were characterized using nitrogen adsorption measurements, X-ray diffraction, Raman and X-ray photoelectron spectroscopies and transmission electron microscopy. Subsequently, ORR activities of the catalysts were determined electrochemically using a conventional three-electrode cell via cyclic voltammetry with a rotating disc electrode, the results of which indicated that the synthesized catalysts had a marked electrocatalytic activity towards ORR in acid media. Among the synthesized catalysts, that functionalized using 2,4,6-tris(2-pyridyl)-1,3,5-triazine as nitrogen source had the highest electrocatalytic activity with the highest onset potential (0.98 V/SHE) and limiting current density (5.12 mA cm−2). The findings are particularly important to determine a non-precious metal catalyst for ORR activity in fuel cells.Iron- and nitrogen-doped graphene catalyst with incorporation of nitrogen using 2,4,6-tris(2-pyridyl)-1,3,5-triazine. (a) High-resolution N 1 s XPS spectrum; (b) TEM image (resolution: 100 nm); (c) oxygen reduction reaction curves in oxygen-saturated 0.5 M H2SO4 at a scan rate of 1 mV s−1.
  PubDate: 2017-02-16T20:55:49.78414-05:0
  DOI: 10.1002/aoc.3738
Effect of lipophilicity of wingtip groups on the anticancer potential of
mono N-heterocyclic carbene silver(I) complexes: Synthesis, crystal
structures and in vitro anticancer study
- Authors: Tabinda Fatima; Rosenani A. Haque, Mohd R. Razali, Ashfaq Ahmad, Muhammad Asif, Mohamed B. Khadeer Ahamed, A. M. S. Abdul Majid
  Abstract: A series of symmetrically n-alkyl-substituted mono benzimidazolium salts with steady increase in n-alkyl chain length have been prepared by stepwise N-alkylation resulting in salts (1–8). The mono N-heterocyclic carbene (NHC)–Ag(I) complexes (9–16) derived from the respective salts were readily accessible by in situ deprotonation using Ag2O. All the salts and the complexes were characterized using Fourier transform infrared, 1H NMR, 13C NMR and elemental analyses. Furthermore, the structures of salts 3 and 7 and complex 16 were elucidated using X-ray crystallography, which established that this mono NHC–Ag(I) complex has a linear bis-carbene arrangement (C2–Ag). The proligands and the respective Ag(I) complexes were studied for their in vitro anticancer potential against human colon cancer cell line (HCT-116) using 5-fluorouracil as a standard. From the IC50 values of all the tested compounds, it can be postulated that there is an influential relationship between the increase in chain length of the wingtip n-alkyl groups and the anticancer potential. The proligands 4–8 and their respective complexes 12–16 with long n-alkyl chain lengths (n = 6–10) showed better IC50 values (0.3–3.9 μM) than the standard drug with the complexes displaying markedly better antiproliferation activity against HCT-116 cell line than the respective proligands and the standard drug (IC50 = 10.2 μM).A series of symmetrically n-alkyl-substituted mono benzimidazolium salts and their corresponding N-heterocyclic carbene silver(I) complexes were synthesized and studied for their in vitro anticancer activity against HCT-116 cells. The anticancer activity was enhanced on increasing the n-alkyl chain length.
  PubDate: 2017-02-16T20:45:39.936514-05:
  DOI: 10.1002/aoc.3735
Carbon nanospheres with well-controlled nano-morphologies as support for
palladium-catalyzed Suzuki coupling reaction
- Authors: Wenhuan Dong; Saisai Cheng, Cheng Feng, Ningzhao Shang, Shutao Gao, Chun Wang, Zhi Wang
  Abstract: Uniform carbon nanospheres (UCS) with well-controlled nano-morphologies were fabricated by hydrothermal carbonization of sucrose in the presence of kayexalate. Highly dispersed and ultrafine palladium nanoparticles were supported on the UCS through a facile co-reduction process with NaBH4 as reducing agent. The obtained Pd@UCS exhibited efficient catalytic activity for the Suzuki coupling reaction. Moreover, the as-prepared catalyst could be recycled and reused at least five times without significant loss of its catalytic activity.With the help of kayexalate, uniform carbon nanospheres (UCS) were prepared by hydrothermal carbonization of an easily obtained biomass source – sucrose. UCS were activated under air condition at 800 °C. Highly dispersed and ultrafine Pd nanoparticles were immobilized on the UCS using NaBH4 solution at room temperature. The final catalyst exhibited good catalytic performance for Suzuki coupling reactions.
  PubDate: 2017-02-15T20:50:34.116544-05:
  DOI: 10.1002/aoc.3741
Inorganic–organic hybrid chitosan-based Schiff base–Ni complex as a
novel, highly efficient and recyclable heterogeneous catalyst for
synthesis of pyrazolophthalazinediones
- Authors: Hossein Naeimi; Sepideh Lahouti
  Abstract: A Schiff base based on chitosan was synthesized through treatment of chitosan and p-dimethylaminobenzaldehyde in methanol solution. This biopolymeric Schiff base was used to prepare a new first row transition metal complex of Ni(II). The biopolymeric Schiff base and the synthesized tetra-coordinated complex were characterized using Fourier transform infrared, 1H NMR and 13C NMR techniques. Then, an efficient synthetic method for functionalized 1H–pyrazolo[1,2-b]phthalazine-5,10-diones was successfully developed using one-pot domino reaction of ninhydrin and malononitrile with 3-arylamino-5,5-dimethyl-2-cyclohexenones catalysed by the chitosan-based Schiff base complex of Ni(II) at room temperature. The advantages of this protocol are easy work-up, short reaction times and high yield of products and also the catalyst can be readily isolated from the reaction mixture and recycled without loss of catalytic activity.Chitosan Schiff base complex of Ni (II) as low toxicity, easy preparation, recyclable catalyst for the synthesis of 1H-pyrazolo [1,2-b] phthalazine-5,10-diones in ethanol was reported.
  PubDate: 2017-02-15T03:25:35.172781-05:
  DOI: 10.1002/aoc.3732
Synthesis and characterization of metal complexes of azo dye based on
5-nitro-8-hydroxyquinoline and their applications in dyeing polyester
fabrics
- Authors: Nadia A. El-Wakiel; Hala F. Rizk, Seham A. Ibrahim
  Abstract: New Mn(II), Ni(II), Co(II) and Cu(II) complexes of an azo dye ligand based on p-phenylenediamine with 5-nitro-8-hydroxyquinoline were synthesized and characterized using elemental analysis, inductive coupled plasma analysis, molar conductance, powder X-ray diffraction, thermogravimetric analysis, magnetic moment measurements, and infrared, 1H NMR, electron ionization mass and UV–visible spectral studies. The spectral and analytical data reveal that the azo dye ligand acts as a monobasic bidentate ligand via deprotonated OH and nitrogen atom of the quinoline ring. The data support the formulation of all complexes with a 2:1 ligand-to-metal ratio, except the Mn(II) complex that has a mononuclear formula. All complexes have an octahedral structure. The molar conductance data reveal that all the metal complexes are non-electrolytic in nature. From the X-ray data, the average particle size of the ligand and its complexes is 0.32–0.64 nm. The colour fastness to light, washing, perspiration, sublimation and rubbing of the prepared ligand and its complexes on polyester fabrics and colorimetric properties were measured. The results reveal that the ligand and its complexes have a good to moderate affinity to polyester fibres.New Mn(II), Ni(II), Co(II) and Cu(II) complexes of an azo dye ligand were synthesized. Spectral and analytical data revealed that the azo dye ligand acts as a monobasic bidentate ligand. X-ray data for the investigated compounds were obtained. The colour fastness of the prepared ligand and its complexes on polyester fabrics and colorimetric properties were measured.
  PubDate: 2017-02-14T21:55:47.799015-05:
  DOI: 10.1002/aoc.3723
Synthesis, characterization, and biological and anticancer studies of
mixed ligand complexes with Schiff base and 2,2′-bipyridine
- Authors: M.M. Omar; Hanan F. Abd El-Halim, Eman A.M. Khalil
  Abstract: New mixed ligand complexes of transition metals were synthesized from a Schiff base (L1) obtained by the condensation reaction of oxamide and furfural as primary ligand and 2,2′-bipyridine (L2) as secondary ligand. The ligands and their metal complexes were studied using various spectroscopic methods. Also thermal analyses were conducted. The mixed ligand complexes were found to have formulae [M(L1)(L2)]Clm⋅nH2O (M = Cr(III) and Fe(III): m = 3, n = 0; M = Cu(II) and Cd(II): m = 2, n = 1; M = Mn(II), Co(II), Ni(II) and Zn(II): m = 2, n = 0). The resultant data revealed that the metal complexes have octahedral structure. Also, the mixed ligand complexes are electrolytic. The biological and anticancer activities of the new compounds were tested against breast cancer (MCF-7) and colon cancer (HCT-116) cell lines. The results showed high activity for the synthesized compounds.Anticancer activities of Schiff base ligand and its mixed ligand complexes for MCF-7 cell line (breast cancer). A new Schiff base ligand and its transition metal mixed ligand complexes were prepared and characterized using various spectral and physicochemical methods. The biological and anticancer activities of the compounds were also investigated.
  PubDate: 2017-02-10T00:50:50.368016-05:
  DOI: 10.1002/aoc.3724
Tin powder-promoted diastereoselective allylation of chiral acylhydrazones
- Authors: Xiansha Peng; Ke-Hu Wang, Danfeng Huang, Juanjuan Wang, Yalin Wang, Yingpeng Su, Yulai Hu, Ying Fu
  Abstract: An efficient method for the allylation of chiral acylhydrazones derived from aldehydes has been developed to give the corresponding allylic hydrazides in good yields and diastereoselectivities. The method uses a combination of tin powder and allylic bromide as allylation system, which avoids the use of toxic allylic stannanes while retaining their merits.An efficient method for the allylation of chiral acylhydrazones derived from aldehydes has been developed to give the corresponding allylic hydrazides in good yields and diastereoselectivities. The method uses a combination of tin powder and allylic bromide as allylation system, which avoids the use of toxic allylic stannanes while retaining their merits.
  PubDate: 2017-02-09T19:55:27.833081-05:
  DOI: 10.1002/aoc.3731
A highly reactive and magnetic recyclable catalyst based on silver
nanoparticles supported on ferrite for N-monoalkylation of amines with
alcohols
- Authors: Ahmad Bayat; Mehdi Shakourian-Fard, Peyman Nouri, Mohammad Mahmoodi Hashemi
  Abstract: Fe3O4@SiO2-Ag catalyst was found to be highly active and selective in the N-alkylation of amines with a variety of aromatic and linear alcohols. The heterogeneous nature of the Fe3O4@SiO2-Ag catalyst allows easy recovery and regeneration by applying an external magnet for six subsequent reaction cycles. The prepared catalyst was characterized using electron microscopy techniques, X-ray diffraction, vibrating sample magnetometry and atomic absorption spectroscopy.A heterogeneous silver catalyst was synthesized for N-alkylation of amines with alcohols. The catalyst can be easily recovered by applying an external magnetic field and used for six reaction cycles without considerable loss of activity. The attractive features of this procedure are excellent yields and operational simplicity.
  PubDate: 2017-02-09T19:50:33.905023-05:
  DOI: 10.1002/aoc.3720
Synthesis, characterization and catalytic application of a new
organometallic oligomer based on polyhedral oligomeric silsesquioxane
- Authors: Eduardo Guimarães Vieira; Rafael Oliveira Silva, Enes Furlani Junior, Newton Luiz Dias Filho
  Abstract: Although homogeneous catalysts provide high performance and selectivity, the difficulty of separation and recycling of these catalysts has bothered the scientific community worldwide. Therefore, the demand for heterogeneous catalysts that possess the advantages of homogeneous ones, with ease of separation and recyclability remains a topic of major impact. The oligomeric catalyst synthesized in this work was characterized using elemental analysis, Fourier transform infrared, 13C NMR, 29Si NMR and energy-dispersive X-ray spectroscopies, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and Brunauer–Emmett–Teller analysis and compared to its homogeneous counterpart [W(CO)3Br2(ATC)] in the epoxidation of 1-octene, cyclooctene, (S)-limonene, cis-3-hexen-1-ol, trans-3-hexen-1-ol and styrene. The results showed that the percentage conversion for the homogeneous species [W(CO)3Br2(ATC)] was slightly higher than for the oligomeric catalyst (POSS-ATC-[W(CO)3Br2]). Furthermore, the selectivity for epoxide of the oligomeric catalyst was greater than that of the homogeneous catalyst by about 25% when (S)-limonene was used. Great conversions (yields) of products were obtained with a wide range of substrates and the catalyst was recycled many times without any substantial loss of its catalytic activity.A new organometallic oligomer catalyst was synthesized from 3-chloropropyltriethoxysilane via a hydrolytic condensation reaction. The catalyst showed very good catalytic activity in the epoxidation of 1-octene, cyclooctene, (S)-limonene, cis-3-hexen-1-ol, trans-3-hexen-1-ol and styrene in the presence of tert-butyl hydroperoxide as oxidant and high selectivity after being used for at least five cycles.
  PubDate: 2017-02-06T21:40:33.422972-05:
  DOI: 10.1002/aoc.3722
Facile fabrication of magnetic MoO2–Salen-modified graphene-based
catalyst for epoxidation of alkenes
- Authors: Zhifang Li; Changlong Yang, Yuanyuan Ma, Peng Li, Jingqi Guan, Qiubin Kan
  Abstract: A facile, green and efficient method for the immobilization of MoO2–Salen onto graphene hybridized with glucose-coated magnetic Fe3O4 nanoparticles is proposed to fabricate a magnetic organic–inorganic hybrid heterogeneous RGO/Fe3O4@C-Salen-MoO2 catalyst for the epoxidation of cyclooctene and geraniol using tert-butyl hydroperoxide or H2O2 as oxidant. Carbon-coated Fe3O4 can improve the stability and add functional ─OH groups on the surface of Fe3O4. The fabricated composite exhibited good performance due to good dispersion of MoO2–Salen active sites. The catalyst can be easily separated from the reaction system using a permanent magnet and used three times without significantly losing its catalytic activity and selectivity.A magnetic organic–inorganic hybrid heterogeneous RGO/Fe3O4@C-Salen-MoO2 catalyst was synthesized using a facile and green method. It demonstrated good performance for the epoxidation of cyclooctene and geraniol due to good dispersion and active site isolation. It was easily recycled using a permanent magnet and used three times without loss of catalytic activity and selectivity.
  PubDate: 2017-02-06T03:05:48.710459-05:
  DOI: 10.1002/aoc.3742
Heteroleptic (N-heterocyclic carbene)–Pd–pyrazole (indazole)
complexes: Synthesis, characterization and catalytic activities towards
C–C and C–N cross-coupling reactions
- Authors: Jin Yang
  Abstract: Eight heteroleptic palladium complexes containing both N-heterocyclic carbenes and NH-heterocycle azoles (pyrazole and indazole) were synthesized and characterized, and their structures were unambiguously confirmed using single-crystal X-ray diffraction. Further investigation of the complexes as catalysts in the Suzuki–Miyaura reaction and Buchwald–Hartwig amination revealed good reactivities for aryl chlorides.Eight heteroleptic (N-heterocyclic carbene)-Pd-(NH-heterocycle azole) complexes were synthesized and used in the Suzuki-Miyaura reaction and Buchwald-Hartwig amination for aryl chlorides.
  PubDate: 2017-02-06T03:01:05.082858-05:
  DOI: 10.1002/aoc.3734
Silver nanoparticle-decorated multiwalled carbon nanotube/pramipexole
nanocomposite: Synthesis, characterization and application as an
antibacterial agent
- Authors: Ghazaleh Shaham; Hojat Veisi, Malak Hekmati
  Abstract: This work reports the preparation of multiwalled carbon nanotube/pramipexole/Ag (CNT/pra/Ag) as a novel antibacterial agent, in which pramipexole groups are utilized as linkers to secure Ag nanoparticles to carbon nanotube surfaces without agglomeration. The resulting CNT/pra/Ag sample was characterized by performing transmission and scanning electron microscopy, wavelength- and energy-dispersive X-ray, X-ray diffraction, Fourier transform infrared, inductively coupled plasma and Raman measurements. Using this approach, monodisperse spherical Ag nanoparticles in CNT/pra/Ag have narrow size distributions with average diameters of ca 3–8 nm. The antibacterial activity of CNT/pra/Ag was investigated against bacterial species Staphylococcus aureus, methicillin-resistant S. aureus, Pseudomonas aeruginosa and Escherichia coli using the paper-disc diffusion method and by determining the minimal inhibitory concentration. CNT/pra/Ag showed better inhibitory activity towards Gram-positive bacteria than Gram-negative bacteria in this study, which indicates its potential as an antibacterial material for laboratory and medical purposes.Pramipexole was successfully bonded on the surface of MWCNTs with subsequent deposition of Ag NPs to produce a novel antibacterial nanocomposite.
  PubDate: 2017-02-06T03:00:57.718685-05:
  DOI: 10.1002/aoc.3737
Eco-friendly synthesis of 3,4-dihydroquinoxalin-2-amine,
diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives with the
aid of MCM-48/H5PW10V2O40
- Authors: Esmail Vessally; Rahim Hosseinzadeh-Khanmiri, Ebrahim Ghorbani-Kalhor, Moosa Es'haghi, Ladan Ejlali
  Abstract: A heterogeneous material composed of MCM-48/H5PW10V2O40 was produced and used as an efficient, eco-friendly and highly recyclable catalyst for the one-pot and multicomponent synthesis of 3,4-dihydroquinoxalin-2-amine, diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives in aqueous media and at room temperature with high yields in short reaction times (40–60 min). The recoverable catalyst was easily recycled at least five times without any loss of catalytic activity. The structures of obtained products were confirmed using 1H NMR and 13C NMR spectra.A heterogeneous material, MCM-48/H5PW10V2O40, was produced and used as an efficient, eco-friendly and highly recyclable catalyst for the one-pot multicomponent synthesis of 3,4-dihydroquinoxalin-2-amine, diazepine-tetrazole and benzodiazepine-2-carboxamide derivatives in aqueous media at room temperature with high yields in short reaction times. The recoverable catalyst was easily recycled at least five times without any loss of catalytic activity. The structures of obtained products were confirmed using 1H NMR and 13C NMR spectra.
  PubDate: 2017-02-06T02:57:27.648502-05:
  DOI: 10.1002/aoc.3729
Syntheses, characterization, antibacterial activity and molecular
modelling of phenylantimony(III) heteroleptic derivatives containing
substituted oximes and piperidine dithiocarbamate
- Authors: Savita Beniwal; Sunil Chhimpa, Deepti Gaur, P.J. John, Yashpal Singh, Jyoti Sharma
  Abstract: Six new heteroleptic phenylantimony(III) derivatives containing substituted oximes and dithiocarbamate moieties of the type (where R = ─C6H5, X = ─CH3 (2a); R = ─C6H4CH3, X = ─CH3 (2b); R = ─C6H4Cl, X = ─CH3 (2c); R = ─C6H4Br, X = ─CH3 (2d); R = ─C6H4OH, X = ─H (2e); R(X)C = (2f)) have been synthesized by the reactions of phenylantimony(III) dichloride with the sodium salt of substituted oximes and dithiocarbamate moiety in unimolar ratio with stirring in dichloromethane. All these newly synthesized derivatives have been characterized using physicochemical and elemental analyses. Structures have been proposed on the basis of infrared, 1H NMR, 13C NMR and LC–MS spectral studies and molecular modelling. In these derivatives the oxime behaves in an unidentate manner whereas dithiocarbamate behaves in a monofunctional anisobidentate manner. Pseudo-trigonal bipyramidal (ψ-TBP) geometry around the antimony metal centre is proposed for these phenylantimony(III) heteroleptic derivatives. The geometry of a representative complex has been optimized through molecular modelling. These newly synthesized derivatives were screened against Bacillus subtilis (Gram-positive) and Escherichia coli (Gram-negative) bacteria to evaluate their antibacterial potential. The structure–activity relationship for antibacterial activity among the four derivatives 2a, 2c, 2e and 2f is discussed.Phenylantimony(III) heteroleptic derivatives containing substituted oxime and dithiocarbamate moiety were synthesized by replacement reactions. Pseudo-trigonal bipyramidal geometry is suggested for these derivatives. The structure–activity relationship among these derivatives is also discussed.
  PubDate: 2017-02-06T02:40:55.104179-05:
  DOI: 10.1002/aoc.3725
Synthesis of carbamates from carbon dioxide promoted by organostannanes
and alkoxysilanes
- Authors: Nicolas Germain; Marko Hermsen, Thomas Schaub, Oliver Trapp
  Abstract: A cooperative methoxy transfer between orthosilicate esters and organotin oxides was developed for the synthesis of various N-alkyl and N-aryl carbamates from carbon dioxide in up to 97% isolated yield. The reaction is highly selective and N-alkylated amines are not observed. Density functional theory calculations of the reaction were performed and, together with NMR observations, a plausible mechanism featuring the catalytic regeneration of dialkyltin dialkoxide is proposed.A synthetic route towards N-alkyl and N-aryl carbamates from carbon dioxide and orthosilicate esters using organotin compounds as catalysts was developed. Isolated yields up to 97% could be achieved and no N-alkylation was observed.
  PubDate: 2017-01-31T03:15:36.461739-05:
  DOI: 10.1002/aoc.3733
A family of silatrane-armed triazole-encapped salicylaldehyde-derived
Schiff bases: Synthesis, spectral analysis, and antimicrobial and quantum
chemical evaluation
- Authors: Gurjaspreet Singh; Aanchal Arora, Sunita Rani, Pooja Kalra, Darpandeep Aulakh, Mario Wriedt
  Abstract: This work describes the successful synthesis of salicylaldehyde-derived Schiff base-linked organosilicon compounds following a highly efficient click approach. Hydroxyl-terminated Schiff bases were alkylated to bis-acetylenes (1–3) which upon 3 + 2 cycloaddition with 3-azidopropyltriethoxysilane yielded triazole-decorated bis-silanes (4–6). These silanes further underwent base-catalyzed transesterification to afford Schiff base-linked triazole-bound organosilatranes (7–9). The final silatranes as well as precursor alkynes and silanes were comprehensively characterized using NMR (1H and 13C) and infrared spectroscopic techniques together with elemental analysis and mass spectrometry of compounds 7–9. Also, the structures of alkynes 1–3 and silatrane 7 were validated using single-crystal X-ray crystallography. Organosilatranes were initially screened for their pharmacokinetic profile using absorption, distribution, metabolism, excretion and toxicity (ADMET) tools and then explored for their antimicrobial activities, with compound 9 emerging as the most potent antimicrobial agent. Compounds 1–3 and 7–9 also underwent thorough computational analysis by applying the density functional theory (DFT) approach with B3LYP/6-31G(d) level of theory and the results were found to be consistent with the experimental data. Several DFT-based descriptors were also evaluated providing a valuable insight into molecular stability and reactivity.This work describes the synthesis of salicylaldehyde-derived Schiff base-linked organosilicon compounds following a highly efficient click approach. The compounds were well characterized using various spectral techniques and also single-crystal X-ray crystallography. The precursor diynes and final silatranes were also subjected to computational analysis. Organosilatranes were further explored for their photophysical properties and antimicrobial activities with compound 9 emerging as the most potent antimicrobial agent.
  PubDate: 2017-01-31T03:05:47.338659-05:
  DOI: 10.1002/aoc.3728
Tetrel bonds, penta- and hexa-coordinated tin and lead centres
- Authors: Sławomir J. Grabowski
  Abstract: A tetrel bond – an interaction between a Group 14 element acting as Lewis acid centre and an electron-donating moiety – is analysed for ZF4 (Z = Sn, Pb) complexes with NH3 and HCN species. MP2/aug-cc-pVTZ calculations were performed and supported by results of the quantum theory of atoms in molecules. The results of calculations show that the tetrel centre may be considered as a pentavalent one if ZF4 interacts with one NH3 or HCN ligand or even as a hexavalent centre if it interacts with two ligands; thus the hypervalency phenomenon is discussed for the complexes analysed here. The theoretical analysis is supported by a discussion of the crystal structures containing the SnF4 fragment; these structures are characterized by a hexa-coordinated tin centre.Tetrel bond – an interaction between a Group 14 element acting as Lewis acid centre and an electron-donating moiety – is analysed for ZF4 (Z = Sn, Pb) complexes with NH3 and HCN species. The Z centre may be considered as pentavalent if ZF4 interacts with one NH3 or HCN ligand or as hexavalent if it interacts with two ligands since all Z─F and Z…N interactions possess covalent character.
  PubDate: 2017-01-31T03:01:09.409554-05:
  DOI: 10.1002/aoc.3727
Copper(II) Schiff Base Complex Immobilized on Superparamagnetic Fe3O4@SiO2
as a Magnetically Separable Nanocatalyst for Oxidation of Alkenes and
Alcohols
- Authors: Marzieh Sarkheil; Maryam Lashanizadegan
  Abstract: A new heterogeneous catalyst containing a copper(II) Schiff base complex covalently immobilized on the surface of silica-coated Fe3O4 nanoparticles (Fe3O4@SiO2-Schiff base-Cu(II)) was synthesized. Characterization of this catalyst was performed using various techniques. The catalytic potential of the catalyst was investigated for the oxidation of various alkenes (styrene, α-methylstyrene, cyclooctene, cyclohexene and norbornene) and alcohols (benzyl alcohol, 3-methoxybenzyl alcohol, 3-chlorobenzyl alcohol, benzhydrol and n-butanol) using tert-butyl hydroperoxide as oxidant. The catalytic investigations revealed that Fe3O4@SiO2-Schiff base-Cu(II) was especially efficient for the oxidation of norbornene and benzyl alcohol. The results showed that norbornene epoxide and benzoic acid were obtained with 100 and 87% selectivity, respectively. Moreover, simple magnetic recovery from the reaction mixture and reuse for several times with no significant loss in catalytic activity were other advantages of this catalystThe new heterogeneous catalyst (Fe3O4@SiO2-Schiff base-Cu(II)) was synthesis. Characterization of this catalyst was performed by FT-IR, XRD, SEM, TEM, EDS, ICP-OES, CHN, TGA and VSM techniques. This catalyst was especially efficient for oxidation of norbornene and benzyl alcohol. The results of catalyst text showed that norbornene epoxide and benzoic acid were obtained with 100 and 87% selectivity, respectively. Simple magnetic recovery from the reaction mixture and reusability for several times were other advantages of this catalyst.
  PubDate: 2017-01-31T02:50:39.994899-05:
  DOI: 10.1002/aoc.3726
Preparation of arylmagnesium/lithium from aryl bromides and their coupling
and substitution reactions in tetrahydrofuran
- Authors: Ozlem Gundogdu; Ramazan Altundas, Yunus Kara
  Abstract: One-pot synthesis of 2-aryltetrahydrofurans was achieved by a coupling reaction between arylmagnesium bromides prepared in situ and tetrahydrofuran under mild conditions. The reaction between ArBr and n-BuLi gave unexpected butylbenzene derivatives in moderate yields.One-pot synthesis of 2-aryltetrahydrofurans was achieved by a coupling reaction between arylmagnesium bromides prepared in situ and tetrahydrofuran (THF) under mild conditions. The reaction between ArBr and n-BuLi gave unexpected butylbenzene derivatives in moderate yields.
  PubDate: 2017-01-31T02:35:41.657108-05:
  DOI: 10.1002/aoc.3719
Palladium–cadmium sulfide nanopowder at oil–water interface as an
effective catalyst for Suzuki–Miyaura reactions
- Authors: S. Jafar Hoseini; Elham Jahanshahi, Roghayeh Hashemi Fath
  Abstract: A simple and effective strategy is described for the synthesis of Pd–CdS nanopowder by the reduction of an organopalladium(II) complex, [PdCl2(cod)] (cod = cis,cis-1,5-cyclooctadiene), in the presence of CdS quantum dots (QDs) at a toluene–water interface. We investigated the impact of addition of CdS QDs on catalytic activity of Pd nanoparticles (NPs). The Pd–CdS nanopowder functions as an efficient catalyst for Suzuki–Miyaura reactions for the formation of carbon–carbon bonds. There is a high electron density on Pd NPs and due to their high electron affinity they behave as an electron scavenger from CdS increasing the rate of oxidative addition, which is the rate-determining step of the catalytic cycle, and, just as we expect, the C─C coupling reaction with the Pd–CdS nanopowder is faster and occurs in less time than that with Pd nanocatalysts. Compared to classical reactions, this method consistently has the advantages of short reaction times, high yields in a green solvent, reusability of the catalyst without considerable loss of catalytic activity and low cost, and is a facile method for the preparation of the catalyst.A toluene–water planar interface was used as an ideal template for self-assembly of Pd–CdS nanopowder as an efficient catalyst for Suzuki–Miyaura cross-coupling reactions.
  PubDate: 2017-01-31T02:31:16.15118-05:0
  DOI: 10.1002/aoc.3718
Ferromagnetic nanoparticle-supported copper complex: A highly efficient
and reusable catalyst for three-component syntheses of 1,4-disubstituted
1,2,3-triazoles and C–S coupling of aryl halides
- Authors: Mohammad Mehdi Khodaei; Kiumars Bahrami, Farhat Sadat Meibodi
  Abstract: A new nanocatalyst was synthesized by immobilization of 4′-(4-hydroxyphenyl)-2,2′:6′,2″-terpyridine/CuI complex on ferromagnetic nanoparticles through a surface modification (FMNPs@SiO2-TPy-Cu). This heterogeneous catalyst was characterized using various techniques including Fourier transform infrared and energy-dispersive X-ray spectroscopies, transmission and scanning electron microscopies, X-ray diffraction, vibrating sample magnetometry and thermogravimetric analysis. The resulting nanocatalyst presented excellent catalytic activity for the regioselective syntheses of 1,4-disubstituted 1,2,3-triazoles and thioethers. The thermally and chemically stable, benign and economical catalyst was easily recovered using an external magnet and reused in at least five successive runs without an appreciable loss of activity.Terpyridine/CuI was immobilized on ferromagnetic nanoparticles. This new nanocatalyst was characterized using various techniques and presented excellent catalytic activity for the regioselective syntheses of 1,4-disubstituted 1,2,3-triazoles in H2O–EtOH and thioethers. The benign and economical catalyst was easily recovered and reused in at least five successive runs.
  PubDate: 2017-01-31T01:50:37.147429-05:
  DOI: 10.1002/aoc.3714
Preparation and characterization of nanomagnetic piperidinium
benzene-1,3-disulfonate ionic liquid as a novel, green and heterogeneous
catalyst and its use in the synthesis of
1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]
pyridazine-5,8-diones under solvent-free conditions
- Authors: Ramin Ghorbani-Vaghei; Jafar Mahmoodi, Yaser Maghbooli
  Abstract: The one-pot four-component synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]pyridazine-5,8-diones was carried out from the reaction between various aldehydes, malononitrile, hydrazine hydrate and phthalic anhydride or maleic anhydride at 110 °C in solvent-free conditions using piperidinium benzene-1,3-disulfonate nanomagnetic ionic liquid (NMIL) as a novel and reusable catalyst. Some advantages of the presented procedure are a significant reduction in cost, effective catalysis and reusability of the catalyst. NMIL was thoroughly characterized using Fourier transform infrared spectroscopy, X-ray diffraction, scanning and transmission electron microscopies, thermogravimetry, derivative thermogravimetry, Brunauer–Emmett–Teller analysis, vibrating sample magnetometry and energy-dispersive X-ray spectroscopy. The technique is developed as a suitable and safe method for the synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]pyridazine-5,8-diones making use of an efficient and reusable green catalyst.One-pot four-component synthesis of 1H–pyrazolo[1,2-b]phthalazine-5,10-diones and 1H–pyrazolo[1,2-a]pyridazine-5,8-diones is reported from the reaction of aldehydes, malononitrile, hydrazine hydrate and phthalic anhydride or maleic anhydride under solvent-free conditions using piperidinium benzene-1,3-disulfonate nanomagnetic ionic liquid as a novel and reusable catalyst. Some advantages of the presented procedure are significant reduction in cost, effective catalysis and reusability of the catalyst.
  PubDate: 2017-01-31T01:11:59.431862-05:
  DOI: 10.1002/aoc.3717
New Rh(III) complexes of 5-methyl-5-(pyridyl)-2,4-imidazolidenedione:
Synthesis, X-ray structure, electrochemical study and catalytic behaviour
for hydrogenation of ketones
- Authors: Seyyed Javad Sabounchei; Mohsen Sayadi, Mojdeh Sadat Hashemi, Ali Hashemi, Davood Nematollahi, Eslam Salahifar, Robert W. Gable
  Abstract: We describe the reaction of anion [RhCl6]3− with a series of hydantoin ligands (HL1, HL2 and HL3 = 5-methyl-5-(2-, 3- and 4-pyridyl)-2,4-imidazolidenedione, respectively). Based on spectroscopic, cyclic voltammetric, elemental and MS analyses, the complexes have the general formula K[RhCl2(L1)2] (1), cis- and trans-K[RhCl4(HL2)2] (2a and 2b) and cis- and trans-K[RhCl4(HL3)2] (3a and 3b). Complexes 2a, 2b, 3a and 3b were characterized successfully using infrared, 1H NMR and 13C NMR spectral analyses. Dissolution of complex 1 in dimethylsulfoxide (DMSO) led to elimination of one KL1 ligand and coordination of two DMSO molecules as ligands and transformation of this complex to cis- and trans-[RhCl2L1(DMSO)2] (1a and 1b). Recrystallization led to separation and isolation of crystals of 1a from the initial mixture. X-ray analysis results showed that this complex was crystallized as solvated complex cis-[RhCl2L1(DMSO)2]DMSO. The catalytic activity of these complexes was then evaluated for the hydrogenation of various ketones.Five new Rh(III) complexes with 5-methyl-5-(pyridyl)-2,4-imidazolidenedione ligands were synthesized and characterized. Single-crystal X-ray diffraction data confirm the octahedral geometry of complex 1a. The Rh(III) complexes 1, 2a, 2b, 3a and 3b were developed as catalysts for hydrogenation of ketones, the catalysts working well at 0.005 mol% loading with conversions up to 95%.
  PubDate: 2017-01-30T03:34:03.555008-05:
  DOI: 10.1002/aoc.3716
Binding interactions of mixed ligand copper(II) amino acid Schiff base
complexes with biological targets: Spectroscopic evaluation and molecular
docking
- Authors: M. Theetharappan; L. Subha, C. Balakrishnan, M.A. Neelakantan
  Abstract: Three mixed ligand copper(II) complexes [Cu(o-vanillin-l-tryptophan Schiff base)(diimine)] (diimine =2,2′-bipyridine (1), 1,10-phenanthroline (2) and 5,6-dimethyl-1,10-phenanthroline(3)) were synthesized and characterized using analytical and spectral methods. The molecular structures of 1–3 were optimized using density functional theory (DFT) at B3LYP/LanL2DZ levels in the gas phase. Spectral and DFT studies suggest a distorted square pyramidal geometry around the copper ion. Binding interactions of 1–3 with calf thymus DNA and bovine serum albumin protein were studied using UV–visible and fluorescence spectroscopies, viscometric titrations and cyclic voltammetry and also using molecular docking analysis. Studies of the binding of the complexes with calf thymus DNA reveal intercalation, which is supported by molecular docking simulation. The DNA cleavage nature of 1–3 with pUC19 DNA shows that the complexes can cleave DNA without any external agents, and the efficiency follows the order 1 > 3 > 2. Synchronous and three-dimensional fluorescence spectral studies suggest that the secondary structures of the protein are altered by the complexes. Antioxidant studies reveal that the complexes have significant radical scavenging activity against DPPH. In vitro cytotoxic activity of the complexes was evaluated against breast cancer cells (MCF-7), revealing that complex 2 exhibits higher cytotoxicity than the other complexes. Nuclear chromatin condensation and fragmentation were observed with DAPI staining assay. The mitochondrial membrane potential damage was studied by FITC staining assay. Flow cytometric analysis suggests that all the metal complexes induce cell apoptosis.Mixed ligand copper(II) complexes containing a Schiff base and diimine co-ligands were synthesized and characterized. Binding interactions of these complexes with DNA and bovine serum albumin protein were evaluated. DAPI and FITC staining assays were used to study the cytotoxicity.
  PubDate: 2017-01-30T00:26:27.09095-05:0
  DOI: 10.1002/aoc.3713
Iron oxide nanoparticles coated with green tea extract as a novel
magnetite reductant and stabilizer sorbent for silver ions: Synthetic
application of Fe3O4@green tea/Ag nanoparticles as magnetically separable
and reusable nanocatalyst for reduction of 4-nitrophenol
- Authors: Hojat Veisi; Fatemeh Ghorbani
  Abstract: Green tea extract having many phenolic hydroxyl and carbonyl functional groups in its molecular framework can be used in the modification of Fe3O4 nanoparticles. Moreover, the feasibility of complexation of polyphenols with silver ions in aqueous solution can improve the surface properties and capacity of the Fe3O4@green tea extract nanoparticles (Fe3O4@GTE NPs) for sorption and reduction of silver ions. Therefore, the novel Fe3O4@GTE NPs nano-sorbent has potential ability as both reducing and stabilizing agent for immobilization of silver nanoparticles to make a novel magnetic silver nanocatalyst (Fe3O4@GTE/Ag NPs). Inductively coupled plasma analysis, transmission and scanning electron microscopies, energy-dispersive X-ray and Fourier transform infrared spectroscopies, and vibrating sample magnetometry were used to characterize the catalyst. Fe3O4@GTE/Ag NPs shows high catalytic activity as a recyclable nanocatalyst for the reduction of 4-nitrophenol at room temperature.Iron oxide nanoparticles coated with green tea extract as a novel magnetite reductant and stabilizer sorbent for silver ions: Synthetic application of Fe3O4@green tea/Ag nanoparticles as magnetically separable and reusable nanocatalyst for reduction of 4-nitrophenol.
  PubDate: 2017-01-30T00:01:28.484475-05:
  DOI: 10.1002/aoc.3711
In situ synthesis of metallophthalocyanines into pores of MIL-101: A novel
and green strategy for preparation of host–guest catalysts
- Authors: Mahmoud Borjian Boroujeni; Alireza Hashemzadeh, Ahmad Shaabani, Mostafa M. Amini
  Abstract: A novel strategy is developed to encapsulate metallophthalocyanines (MPcs, M = Cu, Ni and Co) into MIL-101 to give MPcs@MIL-101 via in situ synthesis of MPcs from component fragments in 1-butyl-3-methylimidazolium bromide as an ionic liquid. This strategy overcomes some drawbacks of existing methods for encapsulation of MPcs into metal–organic frameworks. The chemical and structural properties of MPcs@MIL-101 were determined using scanning electron microscopy, powder X-ray diffraction, and Fourier transformation infrared and flame atomic absorption spectroscopies. The results showed that CuPc@MIL-101, which was used as a ‘ship-in-a-bottle’ catalyst, demonstrates excellent catalytic performance in the oxidative amidation of aldehydes with amine salts. It is confirmed that CuPc@MIL-101 can be reused up to five times without significant loss of its activity.A novel strategy is developed to encapsulate metallophthalocyanines (MPcs) into MIL-101. MPc@MIL-101, which was used as a ‘ship-in-a-bottle’ catalyst, demonstrates excellent catalytic performance in the oxidative amidation of aldehydes with amine salts.
  PubDate: 2017-01-24T01:50:45.194498-05:
  DOI: 10.1002/aoc.3715
Review: Quantitative structure–activity/property relationships as
related to organotin chemistry
- Authors: George Eng
  Abstract: The aim of this review is to examine the current status of quantitative structure–activity/property relationships (QSAR/QSPR) as related to organotin chemistry. QSAR/QSPR are mathematical models that relate some measurable biological activity or physical property in a series of similar compounds to a descriptor or descriptors associated with the molecules. Descriptors used in QSAR/QSPR studies are endless, from traditional parameters to newly developed ones. They range from quantum chemical descriptors to physicochemical parameters while QSAR/QSPR studies range from predicting bio-toxicity of various species to estimating chromatographic parameters. The intent of the review is to provide investigators with the current state of knowledge and trends in this area.A review of quantitative structure–activity/property relationships as pertaining to organotin chemistry is presented. The current state of knowledge and trends are examined.
  PubDate: 2017-01-24T01:45:44.019253-05:
  DOI: 10.1002/aoc.3712