ELECTROCHEMICAL-BEHAVIOR OF 6,6-DIPHENYLFULVENE AND 6,6-DIMETHYLFULVENE IN APROTIC MEDIA

Polarography and cyclic voltammetry were used to study the electroreduction (ER) of 6,6-diphenylfulvene (I) and 6,6-dimethylfulvene (II) in polar aprotic solvents (acetonitrile, DMF, DMSO). It was shown that in solutions with tetraalkylammonium perchlorates as the base electrolyte, the first ER step of fulvenes I and II is the formation of radical-anions (RA) which differ in their stabilities. The RA of fulvene I is stable, yields an anodic peak after reversal of the potential scan, and is converted to the dianion after addition of a second electron. The dimerization reaction is predominant for the RA of fulvene II. The effects of added proton donors and lithium chloride were studied. The ER mechanism of fulvenes I and II was discussed.