Complexes of Mn(II), Co(II), Ni(II) and Cu(II) with 4,4'-bipyridine and dichloroacetates

Abstract

New mixed-ligand complexes with empirical formulae M(4-bpy)L2·1.5H2O (M(II)=Mn, Co), Ni(4-bpy)2L2 and Cu(4-bpy) L2·H2O (where: 4-bpy=4,4'-bipyridine, L=CC L2HCOO-) have been isolated in pure state. The complexes have been characterized by elemental analysis, ir spectroscopy, conductivity (in methanol, dimethylformamide and dimethylsulfoxide solutions) and magnetic and x-ray diffraction measurements. The Mn(II) and Co(II) complexes are isostructural. The way of metal-ligand coordinations discussed. the ir spectra suggest that the carboxylate groups are bonded with metal(II) in the same way (Ni, Cu) or in different way (Mn, Co). The solubility in water is in the order of 19.40·10-3÷1.88·10-3l mol dm-3l. During heating the hydrate complexes lose all water in one step. The anhydrous complexes decompose to oxides via several intermediate compounds. A coupled TG-MS system was used to analyse the principal volatile products of obtained complexes. The principal volatile products of thermal decomposition of complexes in air are: H2O2+, CO2+, HCl+, Cl2+, NO+ and other.