DIMERIZATION OF TRIPHENYLAMINE CATION RADICALS . EVALUATION OF KINETICS USING ROTATING DISK ELECTRODE

The rotated disk electrode (RDE) has unique advantages for studying chemical reactions interposed between successive electron transfers (so-called ECE reactions). A simple modification of previously described digital simulation techniques allows various chemical kinetic complications to be introduced into the basic RDE hydrodynamic equations. These calculations have been applied experimentally to the important class of ECE reactions involving dimerization of cation radicals. The anodic oxidation of several substituted triphenylamines and their subsequent dimerization to tetraphenylbenzidines was studied at a platinum RDE. Second-order rate constants for dimerization in the range 103-104 l. mol-1 sec-1 were readily uncovered.