Electrochemical and thermal studies of the ternary complex of Cu(II) with saccharin and nicotinamide

The electrochemical behaviour and thermal decomposition of a ternary complex of Cu(II) with saccharin and nicotinamide have been investigated by means of voltammetric (square-wave and cyclic voltammetry), spectroscopic and thermoanalysis (TG, DTA, DTG) measurements. The electrochemical data show that the ternary complex undergoes reduction at a more negative potential (−0.310 V) when compared to the binary complexes; Cu(II)–nicotinamide (a shoulder at −0.164 V) and Cu(II)–saccharinate (−0.252 V). ESR spectra (room temperature) of the complex showed a broad signal (g⊥=2.064) due to the weak anti-ferromagnetic coupling between the Cu atoms. ESR and magnetic susceptibility data suggest that the structure of the complex is square–pyramidal in the solid state. The thermal behaviour of the complex from ambient temperature up to 1000 °C in a static air atmosphere was studied. The decomposition pathway of the complex is interpreted in terms of the structural data. A possible mechanism for the decomposition of the complex is proposed.