INVESTIGATION OF A HOMOGENEOUS 2ND ORDER REACTION USING THE ROTATING-DISK ELECTRODE WITH OPTICALLY TRANSPARENT RING

The electrochemical oxidation of N,N,N prime ,N prime -tetraphenyl-p-phenylenediamine to the corresponding quinonediimine is followed by a conproportionation to the semiquinoneimine. The reaction was investigated by spectrophotometry at the rotating disc electrode with optically transparent ring. Working curves relating dimensionless relative extinctions to dimensionless times were calculated by digital simulation for the general reaction scheme A plus or minus ne reversible reaction Q at the disc electrode followed by A plus Q equals 2S in solution. Collection efficiency, material balance, and shape of the working curve exhibited excellent agreement of calcualtions to the experiments. The rate constants of conproportionation were determined at temperatures between 230 K and 300 K.