Electrochemical properties of hetero-cumulenes in acetonitrile

The electrochemical properties of five organic compounds containing a cumulenic functional group (N=C=Y in which Y=N or S or O atoms) have been investigated in acetonitrile at platinum anode. This work examines how various heteroatoms in the cumulenic functional group affect electrochemical parameters. Thus peak potentials, current functions, Tafel slopes, transfer coefficients and number of electrons per molecule have been extracted from cyclic voltammetric measurements. The relative independence of anodic peak potentials of alkylisothiocyanates on the nature of the alkyl group (primary, secondary or tertiary) affords a useful clue as to the predominant electroactive site within the cumulenic functionally. This hypothesis is confirmed by products isolation and characterization. The mechanism for the oxidation of the various functional groups is discussed and supported by both MO computations and preparative electrolysis.