Enolization versus carbonylation at glassy carbon surface through cathodic means

Abstract

The cathodic reduction of ω-bromomethylarylketones in aprotic organic solvents (such as propylene carbonate) containing tetraalkylammonium iodides achieved at smooth glassy carbon (GC) permits through a selective one-electron reduction, the scission of the CBr bond. Quite unexpectedly, the free radical thus formed is prior attached to the carbon surface in its enolic form (GCO(Ar)CCH2). Successive radical addition processes may lead to a redox polymer based on the one-electron oxidation of enol ethers. The average superficial enol concentration at the carbon surface (found to be about 2.5×10−8molcm−2) was assessed by the halogen index (iodine or bromine) via halogen addition to the double bonds followed by the micro-coulometric reduction of the resulting vicinal di-halo compounds.