Dimeric “paddle-wheel” carboxylates of copper(II): Synthesis, crystal structure and electrochemical studies

• DOI: 10.1016/j.poly.2012.11.037
• Publication Date: 2012-12-11T09:45:38Z
• Authors: Muhammad Iqbal; Iqbal Ahmad; Saqib Ali; Niaz Muhammad; Safeer Ahmed; Manzar Sohail
• Keywords: Carboxylate

Abstract The reaction of the sodium salt of para substituted phenyl acetic acid with CuSO 4 in water and subsequent treatment with pyridine gives binuclear centro-symmetric complexes pyCu(R–C 6 H 4 CH 2 COO) 4 Cupy, where R = 4-OMe ( 1 ) and 4-Cl − ( 2 ). The structures of both complexes were solved by X-ray single crystal analysis. The frame of the complexes is constructed as a dimeric ‘paddle-wheel’ with four carboxylate bridges. The apical position is occupied by a pyridine ligand and there is a Cu–Cu bond as well. The compounds demonstrated one-electron redox behavior and their peak currents were found to increase linearly with the square root of the sweep rate ( ν 1/2 ). The overall electrode processes were found to be activation plus diffusion controlled. The values of the formal potential ( E ´ ), diffusion coefficient ( D ) and heterogeneous rate constant ( k °) were evaluated for the electroreduction process for both the compounds.