Synthesis, Crystal Structure, and Properties of a Novel Copper(II) Complex with the Tripod Ligand Tris(2-benzimidazolylmethyl)amine

A novel five-coordinate copper complex with the tripod ligand tris(2-benzimidazolylmethyl)amine (ntb), with composition [Cu(ntb)(H2O)] (ClO4C6H7NO22H2O (C6H7NO2 4-meth- oxylpyridine-N-oxide), was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, I.R., and U.V. The crystal structure of the copper complex has been determined by a single-crystal X-ray diffraction method, and shows that the CuII atom is bonded to a ntb ligand and a water molecule through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry ( = 0.83), with approximate C3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu+2Cu+ couple.