期刊
JOURNAL OF MOLECULAR STRUCTURE
卷 1127, 期 -, 页码 653-661出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.molstruc.2016.08.026
关键词
Pyrazolone; Azo-5-pyrazolone; Oxovanadium complexes; Synthesis; Characterization
资金
- Ordu University, Scientific Research Projects Coordination Department [TF-1455]
Four novel o-hydroxy substituted aryl-(m H, -Cl, Br, CH3) azo-5-pyrazolone compounds (2a-d, respectively) were synthesized as azo-group containing ligands by diazotization of aryl amines then coupled with 1-(4-chlorophenyl)-3-isopropyl-1H-pyrazol-5(4H)-one (1) and the structures were confirmed by FTIR, UV-Visible, GC-MS or ESI-LCMS and NMR spectroscopic techniques. As a result, the first synthesis of azo-5-pyrazolone based oxovanadium(IV) complexes (3a d) was achieved by interaction of 2a d with half equivalent of vanadyl sulphate pentahydrate in a methanolic medium with moderate to high yields (67, 74, 60, 71 for 3a d, respectively). The resulting complexes were characterized using FTIR, UV-Visible, ESI-LCMS and EPR spectroscopic techniques as well as with thermogravimetric (TG/DTG) analysis. They have the composition [VO(L)(2)]center dot H2O; (3a c) or [VO(L)(2)]center dot CH3OH; (3d) where LH is an azo-5-pyrazolone compound as the ligand (2a d). The electronic spectra of the complexes are typical of oxovanadium(IV) complexes showing a low intensity band near 500 nm. Spectroscopic results have shown that azo-5-pyrazolone compounds have acted bidendate and the coordination sites are hydroxyl-substituent on the-azo phenyl-aromatic ring and the pyrazolone carbonyl-moiety. The thermal data confirm that the complexes have methanol (3a c) or water (3d) molecule outside the coordination sphere and the complexes show similar thermogravimetric decomposition fragments which are consistent with the proposed structures. A distorted octahedral geometry has been proposed for these complexes mainly with EPR and the other spectral techniques. (C) 2016 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据