Cobalt(II) and Nickel(II) Complexes with 1-Methyl-2-Pyridin-2-yl-1H- and 1-Methyl-2-Phenyliminomethyl-1H-Benzimidazoles and the closo-Decaborate Anion

Synthesis of cobalt(II) and nickel(II) complexes with the closo-decaborate anion and benzimida-zole derivatives (L-1 = C13N3H11, L-2 = C15N3H13) of the general formula [ML3][B10H10] (M = Co, Ni) is described. Complexes have been characterized by elemental analysis, IR and UV spectroscopy. The structure of a [Ni(L-1)(3)][B10H10] center dot 1.797CH(3)CN single crystal has been determined by X-ray diffraction. The imidazole and pyridine N atoms of three L-1 molecules, two of which are disordered, form the distorted octahedral environment of the Ni atom. In the crystal, the majority of complexes [Ni(L-1)(3)](2+) have the meridional configuration. The Ni-N bonds with the imidazole nitrogen atoms (2.010(4)-2.076(3)angstrom) are shorter than those with the pyridine atoms (2.132(4)-2.179(5)angstrom). This nonequivalence of the Ni-N bonds is responsible for the low magnetic susceptibility of the compound.