Synthesis and crystal structures of six thiocyanato-connected transition metal complexes of 2,2′-biimidazole

Six new complexes ([Cu(NCS)(H(2)biim)](2)(mu-NCS)(2))center dot DMSO (1), (Cu(H(2)biim)(2)(NCS)](SCN)(0.5)(NO3)(0.5) (2), [M(H(2)biim)(3)][M(NCS)(4)]center dot 3DMSO (3-6), (H(2)biim =2,2'-biimidazole, DMSO = dimethyl sulfoxide, M = Cu, Co, Ni, Zn) have been synthesized and characterized by X-ray crystallography. In complex 1, two copper atoms are coordinated by the H2biim ligand and the isothiocyanate ion respectively and they are further bridged by isothiocyanate anions leading to a binuclear structure. Complexes 1, 3-6 are obtained in DMSO/H2O. Complex 2 is obtained in water. In complex 2, the SCN- anion coordinates to Cu(II) atoms with N atom, resulting in compound 2 with the square pyramidal geometry. Complexes 3-6 consist of [Delta-M(H(2)biim)(3)](2+) cations, [Lambda-m(H(2)biim)(3)](2+) cations and [M(NCS)(4)](2-) anions (M = Cu, Co, Ni, Zn). In the six complexes hydrogen bonds R-2(1)(7), N-H center dot center dot center dot O, N-H center dot center dot center dot S and S center dot center dot center dot S intermolecular interaction help to form one to two dimensional structures. (C) 2012 Elsevier Ltd. All rights reserved.