EPR-spectroscopic investigation of the self-exchange electron transfer rate constants and reorganization energies for some electrochemically generated radicals

The electron transfer rate constants for self-exchange reactions between 4-methoxycarbonyl-1-methylpyridinium cation (1(+)) and its radical(1(.)), azulene (2) and azulene radical anion (2(-.)) and 2,5-di-tert-butyl-1,4-dimethoxybenzene (3) and its radical cation (3(+.)) have been investigated by EPR line-broadening measurements in DMF or acetonitrile. The aromatic radicals were generated electrochemically in an improved flow cell. The rate constants were determined in the slow exchange region, and the self-exchange reorganization energies were calculated.