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Li A.-M.,Jingchu University of Technology
Journal of Coordination Chemistry | Year: 2014

Two structurally similar vanadium(V) complexes, [VOL1L] (1) and [VOL2L] (2), where L1 is the dianionic form of N'-(3,5-dibromo-2-hydroxybenzylidene)-4-methoxybenzohydrazide, L2 is the dianionic form of N'-(3,5-dibromo-2-hydroxybenzylidene)nicotinohydrazide, and L is benzohydroxamate, were prepared and characterized by elemental analysis, infrared spectra, and single crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P21/c, with unit cell dimensions a = 12.0262(7), b = 16.5629(9), c = 12.3449(8) Å, β = 105.160(2)°, V = 2373.4(2) Å3, Z = 4, R1 = 0.0376, wR2 = 0.0844, GOOF = 1.058; 2 crystallizes in the monoclinic space group P2 1/c, with unit cell dimensions a = 10.6439(7), b = 16.1968(9), c = 13.1108(8) Å, β = 104.180(2)°, V = 2191.4(2) Å3, Z = 4, R1 = 0.0521, wR2 = 0.1142, GOOF = 1.018. X-ray analysis indicates that vanadium in the complexes are coordinated by phenolate oxygen, imino nitrogen, and enolate oxygen of the hydrazone, two oxygens of the benzohydroxamate, and one oxo, generating octahedral coordination. Oxidations of olefins with the complexes as catalysts were evaluated. The complexes showed effective catalytic efficiency in oxidation of several aliphatic and aromatic substrates under mild conditions, using tert-butyl hydrogen peroxide as oxidant. © 2014 © 2014 Taylor & Francis.


Jin N.-Y.,Jingchu University of Technology
Journal of Coordination Chemistry | Year: 2012

Two new dioxomolybdenum(VI) complexes, [MoO2L 1(CH3OH)] (1) and [MoO2L2(H 2O)] (2), where L1 and L2 are dianionic form of N′-(2-hydroxy- 3-methoxybenzylidene)-4methoxybenzohydrazide and N′-(2-hydroxy- 3methoxybenzylidene)-2-hydroxybenzohydrazide, respectively, have been synthesized and structurally characterized by spectroscopic methods and singlecrystal X-ray determination. The complexes are mononuclear molybdenum(VI) compounds. Mo in each complex is octahedral. The difference in the substituent groups in the benzohydrazides leads to coordination of different solvent molecules. Crystals of the complexes are stabilized by hydrogen bonds. The complexes are effective catalysts for sulfoxidation. © 2012 Taylor & Francis.


Li A.-M.,Jingchu University of Technology
Journal of Coordination Chemistry | Year: 2014

Two new structurally similar molybdenum(VI) complexes, [MoO 2L1(CH3OH)] (1) and [MoO2L 2(CH3OH)] (2), where L1 is the dianionic form of N′-(2-hydroxy-5-nitrobenzylidene)-2-methylbenzohydrazide and L 2 is the dianionic form of N′-(2-hydroxy-4-methoxybenzylidene)- 2-methylbenzohydrazide, were prepared and structurally characterized by elemental analysis, infrared spectra, and single-crystal X-ray diffraction. 1 crystallizes in the monoclinic space group P21/c, with unit cell dimensions a = 7.941(1), b = 14.337(2), c = 15.141(2) Å, β = 92.782(2)°, V = 1721.8(4) Å3, Z = 4, R1 = 0.0286, wR2 = 0.0650, GOOF = 1.028. 2 crystallizes in the triclinic space group P-1, with unit cell dimensions a = 8.003(1), b = 10.608(1), c = 10.880(1) Å, α = 95.745(2)°, β = 97.627(2)°, γ = 105.762(2)°, V = 872.0(2) Å3, Z = 2, R1 = 0.0226, wR2 = 0.0595, GOOF = 1.116. X-ray analysis indicates that Mo in the complexes are coordinated by the phenolate oxygen, imino nitrogen, and enolate oxygen of the benzohydrazone, methanol, and two oxo groups, generating octahedral coordination. The oxidation of olefins with the complexes as catalysts was evaluated, indicating that the complexes showed excellent catalytic efficiency in oxidation of most aliphatic and aromatic substrates under mild conditions using tert-butyl hydrogen peroxide as oxidant. © 2014 © 2014 Taylor & Francis.


He X.-Q.,Jingchu University of Technology
Journal of Coordination Chemistry | Year: 2013

Two new dioxomolybdenum(VI) complexes, [MoO2L 1(CH30H)]CH30H (1) and [MoO2L 2(CH30H)] (2), where L1 and L2 are dianionic forms of N'-(3-bromo-2-hydroxybenzylidene)-4-hydroxybenzohydrazide and N'-(2-hydroxybenzylidene)-2-hydroxy-3-methylbenzohydrazide, respectively, have been synthesized. The complexes have been characterized by elemental analyzes, IR spectra, molar conductance data, and single crystal X-ray determination. Mo in each complex is octahedral. The crystals of the complexes are stabilized by hydrogen bonds and weak π π stacking interactions. The complexes function as effective olefin epoxidation catalysts with hydrogen peroxide as oxidant and sodium hydrogen carbonate as a co-catalyst at room temperature. © 2013 Taylor and Francis.


Zhang H.-X.,Jingchu University of Technology | Liu Y.,Jingchu University of Technology
Steroids | Year: 2014

Introducing amide bonds into a steroid nucleus or its side chain may reduce the acute toxicity and enhance the pharmaceutical activity. In this work, a designed steroidal amide compound, named 3β-hydroxy-17-aza-d-homo-5- androsten-17-one (HAAO), was synthesized and identified. The interactions between HAAO and human serum albumin (HSA) were studied by multiple spectroscopic methods and molecular modeling procedures. It was found that HAAO locates in Sudlow's site I in subdomain IIA of HSA molecules, relying on hydrogen bonds and van der Waals power to form HAAO-HSA complexes at ground state. The number of binding sites, binding constants, enthalpy change (ΔHθ), Gibbs free energy change (ΔG θ) and entropy change (ΔSθ) were calculated at different temperatures based on fluorescence quenching theory and classical thermodynamic equation. The percentages content of the HSA's secondary structures in presence of HAAO were detected by circular dichroism (CD) spectra and compared with those in no presence of HAAO. In addition, the experimental results of both binding site and conformational change were further confirmed by molecular modeling investigation, in which more details of the binding were visually unfolded. The information provided by the study may be useful for designing novel chemotherapeutic drugs and be helpful both in the early stages of drug discovery and in clinical practice. © 2013 Elsevier Ltd. All rights reserved.

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