Synthesis, Structure and Spectral Properties of [Ni(TAMEN)](ClO4)2·DMF (TAMEN = N,N′-Tetra(4-antipyryl-methyl)-1,2-diaminoethane), a Mannich Base Complex of Biological Relevance

The new mononuclear complex [Ni(TAMEN)](ClO4)2·DMF (TAMEN = N,N′-tetra-(4-antipyrylmethyl)-1,2-diaminoethane) has been synthesized and its crystal structure was determined by single-crystal X-ray diffraction. It crystallizes with monoclinic symmetry, space group P21/c (no. 14) and unit cell parameters of a = 10.8736(3), b = 10.9560(4), c = 45.820(2) A, β = 90.23(1)°, Z = 4. The TAMEN molecule acts as a hexadentate ligand incorporating a 1,2-diaminoethane bridge in the staggered conformational gauche isomer. The nickel(II) ion is octahedrally coordinated with metal-ligand distances ranging from 2.023(2) to 2.145(3) A. Electronic and vibrational spectroscopy data agree well with the crystal structure.