Prediction of reactive sites for the electropolymerization of p‐benzenesulfonic acid derivatives: Ab initio and experimental study

Abstract

ABSTRACT:A theoretical study of the electronic structure of some p-benzenesulfonic acid derivatives is carried out to explain the electrooxidation of these compounds, in particular the allyl ether p-benzenesulfonic acid, sodium salt electrooxidation, and electrode surface modification observed during electrochemical studies. The effects of the alkyl side chain and of the aromatic ring during electrooxidation are considered using the UHF and B3LYP levels of theory. The changes in monomer structure after removal of an electron are explained by the nodal structure of the highest occupied molecular orbital (HOMO), ␣ and ␤ single occupied molecular orbitals (SOMO) and by their energies. Apart from frontier molecular orbital theory, charge reaction control, which is expected to occur at higher oxidation potentials, is also discussed. The calculations indicate that the unpaired electron spin distribution and atomic charge variation in the radical cation is very sensitive to the nature of the alkyl side chain. In fact, this distribution reflects the electronic structure of these monomers related to their oxidability. It is shown that the removal of an electron is carried out by two competing mechanisms.

A New Voltammetric Sensor Based on a Glassy Carbon Electrode Modified with 8‐Hydroxyquinoline‐5‐sulfonic Acid

“…It was already demonstrated that its polymerization can be achieved by enzyme‐catalysis 10, that some of its analogues can be electropolymerized 11–14, and that it can be absorbed onto pyrolytic graphite electrode 15.…”