Electrochemical Studies on Complexes of Copper (II) with Anticoagulant Warfarin sodium

Electrochemical studies on complexes of copper(II) with Warfarin sodium have been carried out by direct current polarography. Using D.M.E. electrode the comparative investigation on the electroreduction of copper(II) with Warfarin sodium in 1M KNO3 containing 30% and 40% ethanol have been made. The voltammetric data were evaluated according to Deford and Hume's method. The reduction was reversible and diffusion controlled involving 2e – in each case. Deford and Hume's treatment suggests that Warfarin forms 1 : 1 complexes at 25° and 1 : 1, 1: 2 at 35°C in 30% ethanol. Further, in 40% ethanol 1 : 1 and 1 : 2 complexes are identified at both temperatures. The values of stability constants (log ) obtained are 5.0973 at 25°C, 5.0557, 5.6720 at 35°C in 30% ethanol 5.2532, 9.8783 at 25°C and 5.2222, 9.7500 at 35°C in 40% ethanol. Thermodynamic functions (G°, H°, S°) have also been reported.