Syntheses, Spectra, Thermal Studies and Crystal Structures of Vitamin B13 Complexes of Nickel(II) with N,N,N ',N '-Tetramethylethylenediamine and 2,2-Dimethylpropane-1,3-diamine

Abstract

Two nickel(II) complexes of vitamin B13 (H(3)Or) with N,N,N',N'-tetramethylethylenediamine (tmen) and 2,2-dimethylpropane-1,3-diamine (dmpen) were synthesized and characterized by means of elemental and thermal analyses, magnetic susceptibility, and IR and UV/Vis spectroscopic studies. The crystal structures of mer-[Ni(HOr)(H(2)O)(2)(tmen)]center dot H(2)O (1) and [Ni(HOr)-(dmpen)(2)] (2) were determined by using single-crystal X-ray diffraction. In the complexes, which crystallize in the triclinic system (space group P (1) over bar for 1) and the monoclinic system (space group P2(1)/c for 2), the Ni(II) ions exhibit a distorted octahedral coordination. Ni(II) ions are chelated by the deprotonated nitrogen atom of the pyrimidine ring and the oxygen atom of the carboxylate group, the distorted octahedral coordination completed by one tmen and two aqua ligands for 1 or two dmpen ligands for 2.