کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1308732 975180 2009 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Synthesis, structural, spectroscopic and thermal characterization of cobalt complexes with 3- and 6-methylpicolinic acid. Voltammetric and spectrophotometric study in solution
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی معدنی
پیش نمایش صفحه اول مقاله
Synthesis, structural, spectroscopic and thermal characterization of cobalt complexes with 3- and 6-methylpicolinic acid. Voltammetric and spectrophotometric study in solution
چکیده انگلیسی

Cobalt complexes of 3- and 6-methylpicolinic acid, namely [Co(3-Mepic)3] (1) and [Co(6-Mepic)2(H2O)2] · 2H2O (2) were prepared and characterized by spectroscopic methods (IR, UV–Vis, NMR), their molecular and crystal structures were determined by X-ray crystal structure analysis and their thermal stability by TGA/DTA methods. Square-wave voltammetry showed that on mercury electrode the oxidation of 2 requires higher potential than the oxidation of complex anion [Co(3-Mepic)3]−, the most probable product of the reduction of 1. The reduction of 1 and the oxidation of 2 depend on the kinetics of electron transfer and the electrode material. X-ray structural analysis revealed octahedral coordination polyhedron in both 1 and 2 and the same N,O-chelated coordination mode for both ligands. 13C, 1H and 15N NMR spectroscopy confirmed that coordination mode of 3-methylpicolinic acid in 1 in DMSO solution. UV–Vis spectrophotometric measurements were used to study the complexation of cobalt with 3- and 6-methylpicolinic acid in aqueous solution and to determine the composition of the formed complexes by Job method of continuous variation. The stoichiometry of the complex with 3-methylpicolinic acid is 2:3, while it is 2:3 and 3:2 for the complex with 6-methylpicolinic acid, indicating the possibility of the formation of more than one complex species.

Two cobalt complexes with 3- and 6-methylpicolinic acid were prepared and characterized by spectroscopic and thermal methods, while their crystal structures were determined by X-ray structural analysis. Complexes were studied by voltammetric methods and their formation and composition were determined by spectrophotometric measurements in solution.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Inorganica Chimica Acta - Volume 362, Issue 8, 1 June 2009, Pages 2704–2714
نویسندگان
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