Synthesis of S,S′- Bis (2-Benzimidazolylmethyl)Dithioglyoxime and Its Complexes with Nickel(II), Palladium(II), Cobalt(II), and Cobalt(III)

Abstract

A new vicinal dioxiroe ligand with two 2-benzimidazolylmethyl groups, namely S,S′-bis(2-benzimidazolylroethyl)dithioglyoxime (H₂L), has been prepared from cyanogen-di-N-oxide and 2-mercaptomethylbenz-imidazole in dichloromethane at -10°C. Nickel(II), palladium(II), cobalt(II) and cobalt(III) complexes of H₂L have a metal : ligand ratio of 1 : 2 and the ligand coordinates through the two N atoms, as most of the vicinal dioximes. [Co(HL)₂(L′)Cl] has been prepared with L′ = pyridine, 2,6-dimethylpyridine, 2-mercaptopyridine, 2-car-boxypyridine, pyridine-2-carboxyaldehyde, triphenylphosphine, tri-phenylarsine, together with a chloride ion as axial ligands. All these complexes are slightly soluble in common organic solvents. Structures are proposed according to elemental analyses, ¹H, ¹³C-NMR IR, and UV-Visible spectral data.