Abstract
The polarographic behavior of the five phenyl‐substituted ethenes (styrene, stilbene, 1,1‐diphenylethylene, triphenylethylene, and tetraphenylethylene) at the dropping mercury electrode has been examined in dimethylformamide (DMF) and DMF‐water solution containing 0.2M tetra‐n‐butylammonium iodide as background electrolyte on the basis of the various criteria for reversibility based on direct current polarography. Heterogeneous rate constants and 
values have been calculated on the basis of the spherical expanding electrode theory.
None of the reversibility criteria predictions for the various possible mechanisms are entirely in accord with the experimental results. Although polarographic reduction of the phenyl‐substituted ethenes is indicated to occur by processes which involved a change of electron transfer mechanisms, a definite decision regarding the actual mechanisms cannot be reached because of the lack of adequate theoretical bases for such a mechanism change and for the effects of variation in double layer structure on any given mechanism.