Statistical copolymers of thiophene-3-carboxylates and selenophene-3-carboxylates; Se-77 NMR as a tool to examine copolymer sequence in selenophene-based conjugated polymers

Autor(es)

Kawakami, Manami ; Schulz, Karl H. G. ; Varni, Anthony J. ; Tormena, Claudio F. ; Gil, Roberto R. ; Noonan, Kevin J. T.

• Tipo de documento: Artigo Científico
• Fonte: Polymer Chemistry; v. 13, n. 37, p. 9-pg., 2022-08-09.

Resumo

Herein, we demonstrate that homopolymerization and statistical copolymerization of 2-ethylhexyl thiophene-3-carboxylate and 2-ethylhexyl selenophene-3-carboxylate monomers is possible via Suzuki-Miyaura cross-coupling. A commercially available palladium catalyst ([1,3-bis(2,6-di-3-pentylphenyl)imidazol-2-ylidene](3-chloropyridyl)dichloropalladium(ii) or PEPPSI-IPent) was employed to prepare regioregular conjugated polymers with high molecular weights (similar to 20-30 kg mol(-1)), and relatively narrow molecular weight distributions. The optical bandgap in the copolymer series could be reduced by increasing the concentration of selenophene-3-carboxylate in the material. Configurational triads were observed in the H-1 NMR spectra of the statistical copolymers, which were assigned using a combination of 2D NMR techniques. The use of a H-1-Se-77 HSQC spectrum to further examine sequence distribution in the statistical copolymers revealed how Se-77 NMR can be used as a tool to examine the microstructure of Se-containing conjugated polymers. (AU)

• Processo FAPESP: 20/10246-0 - Ressonância magnética nuclear: das sequências de pulso a determinação estrutural
• Beneficiário: Claudio Francisco Tormena
• Modalidade de apoio: Auxílio à Pesquisa - Temático