Substitution effect of phenol derivatives on electrochemical oxidation potentials: Correlation of theoretical reaction Gibbs free energies

Reaction Gibbs free energies for electron abstraction from phenol and its 74 derivatives were calculated using the composite ab-initio approach (G4) in combination with the implicit solvation model. Resulting values were correlated with 38 oxidation potentials obtained from cyclic voltammetry measurements. Substitution effect and the role of substituents in ortho-, meta-, and para-position were also quantified by Hammett constants. The evaluated linear dependences can be used to reliably estimate electrochemical potentials of substituted phenols solvated in water.