Features of the formation of d10 metal complexes with benzimidazoles derivatives in the presence of the closo-decaborate anion

Abstract

Copper(I) complexation with luminophore ligands 1–(1–methylbenzimidazol-2-yl)-N-phenylmetanimine (L1), 1-ethyl-2-(4-methoxyphenyl)azobenzimidazole (L2) and 1-(1-benzylbenzimidazol-2-yl)-N-cyclohexylmethanimine (L3) with different types of the linker group and different functional substituents has been studied in the presence of the closo-decaborate anion. For comparison, a number of zinc(II) and cadmium(II) complexes with the [B10H10]2− anion and ligand L3 has been isolated and characterized. The effect of the nature of the complexing metal on the composition and structures of final complexes has been determined. For Zn(II), a tris-chelate complex was obtained with the boron cluster acting as a counterion. In the case of Cd(II) and Cu(I), mononuclear and binuclear complexes have been obtained, respectively, with the boron cluster anion [B10H10]2− coordinated by the metal atom via 3c2e (CdHB and CuHB) bonds. The structures of complexes [Zn(L3)3][B10H10]∙4CH3CN, [Cd(L3)2[B10H10]]∙2CH3CN, [Cu2(L2)2[μ–B10H10]] and [Cu2(L3)2[μ-B10H10]] have been determined by single-crystal X-ray diffraction. An analysis of the electronic absorption spectra of the obtained compounds indicates that the luminophore properties of ligands L are retained in the complexes under consideration.