Base effects on electrochemical oxidation of indoline

The electrooxidation of indoline was studied as the first step in exploring its utility as a model liquid hydrogen carrier. Electrochemical oxidation of indoline in the presence of nitrogen-containing bases resulted in a cathodic shift in the onset of the oxidation. A linear correlation was found between the pKa of the base and the magnitude of the cathodic shift of indoline oxidation. A hydrogen bonding complex model is proposed to account for this effect, and 1H NMR spectroscopy and cyclic voltammetry experiments were conducted to support this proposed mechanism.