Copper(II) and nickel(II) complexes of binucleating N,N′-disubstituted imidazole-4,5-dicar☐amides

Abstract

Several copper(II) and nickel(II) complexes are prepared from N,N′-disubstituted imidazole-4,5-dicar☐amides [substituent = 2-(dimethylamino)ethyl, 3-(dimethylamino)propyl, 2-pyridylmethyl, and 2-(2-pyridyl)ethyl; abbreviated as H 2L collectively or H 2aei, H 2api, H 2pmi, and H 2pei, respectively]. Copper(II) forms two types of complexes: CuL·nH 2O and Cu 2LCl 2·nH 2O, both of which are magnetically subnormal. The temperature-dependent magnetic susceptibilities of CuL·nH 2O are compatible with an imidazolate bridged tetramer while those of Cu 2LCl 2·nH 2O are compatible with an imidazolate bridged dimer. Nickel(II) afforded only Ni(Hpmi)(NCS) and Ni 3(pei) 2 (NCS) 2·8H 2O. The former is a diamagnetic, square planar monomer, while the latter consisted of one octahedral and two square planar nickel(II) centres bridged by an imidazolate moiety. The latter is a rare example of complexes containing metal ions in different stereochemistries and spin states.