Synthesis, Crystal Structure, and Properties of a Novel Copper(II) Complex with the Tripod Ligand Tris(N-Methylbenzimidazol-2-ylmethyl)Amine and 2-Methacrylate

Abstract

A novel five-coordinate copper complex with the tripod ligand tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) and 2-methacrylate, with the composition [Cu(Mentb)(2-methacrylate](ClO4)· 2DMF· 0.5H2O, was synthesized and characterized by means of elemental analyses, electrical conductivities, thermal analyses, IR, and UV. 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 tris(N-methylbenzimidazol-2-ylmethyl)amine (Mentb) ligand and a 2-methacrylate molecule through four N atoms and one O atom, giving a distorted trigonal-bipyramidal coordination geometry (τ = 0.78), with approximate C3 molecular symmetry. Cyclic voltammograms of the copper complex indicate a quasireversible Cu+2/Cu+ couple. Electron spin resonance data confirm the trigonal-bipyramidal structure and indicate g‖ < g∞ with a very small value of A (23 × 10−4 cm−1).