C-C coupling of polymer chains in thin films of oxidized polypyrrole doped by BF4− and PF6− anions: Quantum chemical modeling

• Published in: Journal of solid state electrochemistry Vol. 28; no. 5; pp. 1585 - 1599
• Main Authors: Zyubina, Tatyana S., Zyubin, Alexander S., Istakova, Olga I., Talagaeva, Nataliia V., Vorotyntsev, Mikhail A., Konev, Dmitry V.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2024; Springer Nature B.V
• Subjects: Analytical Chemistry; Anions; Aqueous electrolytes; Chains (polymeric); Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Condensed Matter Physics; Covalent bonds; Electrochemistry; Electrodes; Energy Storage; Infrared spectroscopy; Monomers; Nonaqueous electrolytes; Original Paper; Physical Chemistry; Polymerization; Polymers; Polypyrroles; Quantum chemistry; Thin films; Conjugated polymer; Interaction of polymer chains; Electroactive materials; Doping anions; C–C interchain coupling; Electropolymerization; Polypyrrole; Quantum chemical modeling
• DOI: 10.1007/s10008-023-05756-8
• ISSN: 1432-8488

Oligopyrrole-acceptor (BF 4 or PF 6 ) complexes, i.e., positively charged oligopyrrole ( OPy ) clusters with BF 4 − or PF 6 − doping anions, represent a model of a charged region of the polymer chain inside a polypyrrole film deposited on the electrode surface via electropolymerization of the pyrrole monomer in a non-aqueous electrolyte containing BF 4 − or PF 6 − anions. The ratio of 4 to 1 used in the calculation for the ratio of the monomer units-to-anion numbers has been chosen in accordance with the typical electronic charge of the polymer chain (about + 0.25 per monomer unit) for polypyrrole films on the electrode surface at a potential close to the polymerization one. Interaction between such oligopyrrole complexes inside polymer chains in thin films near the electrode surface is considered. Calculations have been performed for the variants: PBE/PAW, ωB97XD/6-31G(d,p), and M062X/6-311+G(2d,p), taking into account periodic conditions as well as in the cluster approximation. It has been shown that such interactions can lead to the new C–C bond formation under certain conditions. Based on calculations of IR spectra of such systems, manifestation of such structures in the form of an intense peak in the region of 1700–1740 cm −1 has been revealed.