Molecular modeling study on the possible polymers formed during the electropolymerization of 3-hydroxyphenylacetic acid

The compound 3-hydroxyphenylacetic acid (3-HPA) has been used as a monomer in the synthesis of polymeric films by electropolymerization; these films serve as supports for the immobilization of biomolecules in electrochemical biosensors. To assist in the elucidation of the mechanism of 3-HPA electropolymerization, a systematic quantum mechanical study was conducted. In addition to the monomer, all possible intermediates and the probable oligomers formed during the electropolymerization were investigated using a density functional theory (DFT) method combined with a previous conformational analysis performed with the aid of the RM1 semi-empirical method or a Monte Carlo conformational analysis with the force field OPLS-2005. From the data analysis combined with the experimental results, a mechanism was proposed for the main route of formation of the polymeric films. The mechanism involves the formation of polyethers from the coupling of phenoxide radicals and radicals based on the aromatic ring.

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► DFT study on the electropolymerization of 3-hydroxy phenylacetic acid.
► Proposed reaction mechanism, based on theoretical and experimental evidence.
► Conformational analysis of oligomeric models.
► Calculation of oligomers IR spectra for validation of the mechanistic proposal.