Experimental and Theoretical Analysis of the Electrochemical Oxidation of Catechol and Hydroquinone Derivatives in the Presence of Various Nucleophiles

Abstract

Electrochemical oxidation of some catechol and hydroquinone derivatives has been investigated both experimentally and theoretically to bring hints into the connection of thermodynamic and oxidation potential. The theoretical results were calculated at DFT (B3LYP, BP86) levels of theory and 6–311G (p,d) basis sets. In this study we focus on the mechanisms of the electrochemical oxidation of catechol in the presence of various nucleophiles. A general thermodynamic cycle, which is proposed to calculate ΔG of oxidation of the intermediates and products, introduces thermodynamic as one of the important parameters on the reaction mechanisms. The results of this work show that electrochemical oxidation potential of studied compounds is directly dependent on the ΔG of electrochemical oxidation. Also it was found that depending on the ΔG of electrochemical oxidation, the products which are produced on the surface of electrode will participate in the electrochemical or chemical following reactions. Finally we can consider several mechanisms in the electrochemical oxidation of catechol in the presence of different nucleophiles.