Crystal Structures and Characterization of Cobalt(II), Manganese(II), and Zinc(II) Complexes of 2-[Bis(2-benzimidazolylmethyl)amino]ethanol

Cobalt(II), manganese(II), and zinc(II) complexes with the tripodal ligand, 2-[Bis(2-benzimidazolylmethyl)amino]ethanol, bbt, were prepared and characterized by infrared and electronic spectra, magnetism, and conductivities. Their crystal structures were determined by X-ray diffraction method. Crystal data: [Co(bbt)(NCS)2] (1), space group P212121(orthorhombic), a=12.881(1), b=17.970(2), c=9.076(1) A; [Mn(bbt)(NCS)2](2), space group P212121(orthorhombic), a=18.179(2), b=13.073(2), c=9.097(2) A; [Zn(bbt)(NCS)2](3), space group P21/ a(monoclinic), a=15.421(4), b=14.803(4), c=10.589(3) A, β=115.81(2)°. The final R values are 0.044 (1), 0.054 (2), and 0.079 (3), for non-hydrogen atoms. The coordination geometries of 1 and 2 can be described as a distorted octahedron. In 3, the alcoholic oxygen of bbt is not in coordination, hence the zinc ion is five-coordinated forming a highly distorted trigonal bipyramid. In all the complexes, thiocyanate ions coordinate in cis form with the nitrogen atoms. The magnetic me...