Synthesis, structure, spectroscopic and electrochemical properties of bis(histamine-saccharinate) copper(II) complex

Abstract

Crystal structure of [Cu(hsm)(2)(sac)(2)] (hsm is histamine and sac is saccharinate) complex has been determined by X-ray diffraction analyses and its magnetic environment has been identified by electron paramagnetic resonance (EPR) technique. The title complex crystallizes in the monoclinic system, space group P 21/c with a = 7.4282(4), b = 22.5034(16), c = 8.3300(5) angstrom, beta = 106.227(4)degrees, V = 1336.98(14) angstrom(3), and Z = 2. The structure consist of discrete [Cu(hsm)(2)(sac)(2)] molecules in which the copper ion is centrosymmetrically coordinated by two histamine ligands forming an equatorial plane [Cu-N-hsm = 2.024(2) and Cu-N-hsm 2.0338(18) angstrom). Two N atoms from the saccharinate ligands coordinate on the elongated axial positions with Cu-N-sac being 2.609(5) angstrom. The complex is also characterized by spectroscopic (IR, UV/Vis) and thermal (TG, and TDA) methods. The cyclic voltammogram of the title complex investigated in DMSO (dimethylsulfoxide) solution exhibits only metal centred electroactivity in the potential range -1.25-1.5 V versus Ag/AgCl reference electrode. The molecular orbital bond coefficients of Cu(II) ion in d(9) state is also calculated by using EPR and optical absorption parameters. (c) 2006 Elsevier B.V. All rights reserved.