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

摘要

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℃, 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℃ and 230.0℃ 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 ofΔE 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.