Thermal behaviour of biologically interesting coordination compounds of benzimidazole with divalent metal ions

Abstract

The imidazole nucleus and its related structures, especially benzimidazole, are known to play a crucial role in the structure and functioning of a number of biologically important molecules, generally by virtue of their ability to coordinate to metal ions. Different parameters such as basicity of the ligands, π-acceptor ability, steric factors, hydrogen bonding, etc., influence either the structures or the thermal characteristics of the coordination compounds obtained by reaction of imidazole and benzimidazole with transition metal ions. The thermal properties of coordination compounds obtained by reaction of benzimidazole with Co(NO 3) 2 Ni(NO 3) 2 and Cu(NO 3) 2 are studied here by means of thermoanalytical techniques, supported by IR and reflectance spectroscopy, and compared with the previously published results for the coordination compounds obtained by reaction of the same ions with imidazole and N-methylimidazole. The compounds obtained were Me(LH) n (NO 3) 2 and Me(L) 2 (Me Co II, Ni II, Cu II; n = 2 or 4).