Low Temperature Studies of Electrochemical Kinetics I. Cyclic Voltammetry of Diethyl Fumarate

Descriptive, low temperature, cyclic voltammetry studies have been con-ducted upon diethyl fumarate (DEF) in dimethylformamide (DMF). Tem-perature variations down to 200 ~ reveal three, interrelated, reduction proc-eSses. The first and second correspond to the formation of DEF and DEF=; the third is attributed to the reduction of a dimeric product of the initial reduction. Temperature r duction inhibits the formation of this dimeric product while enhancing the availability of DEF- for reduction to DEF = The extensive formation of DEF = at reduced temperatures appears to be ac-companied by a filming of the electrode surface. This suggests that polymeriza-tion may proceed through DEF = and may actually be inhibited by the di-merization process. The addition of water enhances the third reduction peak; it also decreases the available cathodic potential range so that this peak be-comes lost in background at room temperature. Temperature reduction in-creases the available potential range so that products of the water-accelerated electrohydrodimerization reaction may be studied. The electrohydrodimerization (EHD) reactions of 1,2-diactivated olefins have been studied by many in-vestigators. These EHD reactions are of synthetic in-terest because they are generally regarded as the first step in the formation of the "living " polymer (1). Recent studies (2-4) have also indicated that these re-actions may also be used to electroinitiate certain cyclizations. The olefins used in these studies are of the ior