Abstracto

Iridium(III) catalysis of oxidation of oxalic acid and malic acid by QFC in acidic medium

Sheila Srivastava*, Parul Srivastava

Kinetic investigation inRu(III) catalyzed oxidation of oxalic acid andmalic acid in an acidified solution of quinolinium fluorochromate (QFC) has been studied in the temperature range of 30ï‚°-45ï‚°C. Increase in concentration of oxidant and Cl- ion showed fractional positive order. First order kinetics was observed in case of catalyst Ir(III) and substrate, [IrCl6]-3 being reactive species of catalyst. The influence of [H+], and ionic strength on the rate was found to be insignificant. The main product of oxidation of oxalic acid andmalic acid are carbon dioxide and oxoacid respectively. The reaction has been studied in ten different solvents. The various thermodynamic parameterswere calculated fromrate measurements at 30, 35, 40 and 45ï‚°C respectively. A suitable mechanism in conformity with the kinetic observations has been proposed and the rate law is derived on the basis of obtained data.