Kinetics and Mechanism of Palladium Catalysed Electron Transfer Reaction between Glutathione (Reduced) and Pyridinium Chlorochromate in Acid Medium

The palladium (Pd +2 ) catalysed electron transfer reaction between glutathione (reduced) (GSH) and pyridinium chlorochromate (PCC) has been studied spectrophotometrically over the range 2.00 � 10 3 (GSH) � 6.00, 0.01 � (H + ) � 0.03 mol dm -3 , 2.83 � 10 5 (Pd +2 ) � 14.15 and 20 0 Ct � 40 0 C. The rate of reaction was found to increase with the increase in (GSH) T, (H + )T and (Pd +2 ). The reaction was found to exhibit first order dependence in (GSH) T , (H + )T and (Pd +2 )T. TheH � (kJ/mol) and �S � (JK -1 mol -1 ) for the electron transfer reaction were found to be -27.7 and -243.9. The product of the reaction was found to be glutathione disulfide (GSSG) as indicated by infrared spectrum. The negative values of activation parameters favour the formation of the ordered transition state.