Thermal stability and electrochemical behaviour of Tetrakis-μ-benzoatodicopper(II)

Abstract

Abstract Copper(II) benzoate (CuB) was synthesized and structurally characterized to have a binuclear, paddle-wheel structure. The complex was found to be thermally stable up to 230°C, and underwent four stages of decomposition, loss of CO2, C6H6, CH3CH2-OCH2CH3 and some aliphatic unsaturated organic materials. The DSC curve shows two endotherms at 80.0°C and 230.0°C respectively, indicating that the initial weight loss can be attributed to solvated molecules and the starting of the major decomposition process, (shown in the TG analysis). Cyclic voltammetry studies in a mixed-solvent system of methanol and ethanoic acid (20:1 v/v) show three cathodic peaks, at −0.13 V, −0.35 V and −0.74 V, representing a step-wise electron transfer process, and two overlapping anodic peaks at +0.31 V and +0.46 V. The high value of ΔE ranging from 400 mV to 1200 mV indicates that the redox process is accompanied by an extensive structural reorganization of the complex in the solution creating a different geometrical environment around the central copper ion.