Boron Cluster Anion [B12H12]2– in Zinc(II) and Cadmium(II) Complexation at the Presence of N-Donor Heterocyclic Ligands

Zinc(II) and cadmium(II) complexation with the dodecahydrido- closo -dodecaborate anion [B 12 H 12 ] 2– in the presence of benzimidazole ligands 1-methylbenzimidazo-2-yl-methyleneaniline (L 1 ) and 1-ethyl-2-(4-methoxyphenyl)azobenzimidazole (L 2 ) was studied. A number of Zn(II) and Cd(II) complexes with the [B 12 H 12 ] 2– anion and ligands L 1 or L 2 were obtained and characterized. Effect of the metal nature on the composition and structure of the resulting compounds was determined. Only tris-chelate zinc(II) complexes with the [B 12 H 12 ] 2– anion were isolated. For cadmium, first examples of mixed-ligand complexes with the [B 12 H 12 ] 2– anion coordinated by the metal atom via 3c2e (CdHB) bonds were isolated. Structures of complexes [Zn(L 1 ) 3 ][B 12 H 12 ]·2CH 3 CN, [Cd(L 1 ) 2 [B 12 H 12 ]]·2CH 3 CN and [Cd(L 2 ) 2 (CH 3 CN)[B 12 H 12 ]]·CH 3 CN were determined by X-ray diffraction. Graphical Abstract