Photoacidity as a tool to rationalize excited state intramolecular proton transfer reactivity in flavonols

Autor(es)

Teixeira Alves Duarte, Luis Gustavo ^{[1, 2]} ; Germino, Jose Carlos ^[2] ; Braga, Claudia de Avila ^[1] ; Barboza, Cristina Aparecida ^[3] ; Zambon Atvars, Teresa Dib ^[2] ; Santos, Fabiano da Silveira ^[1] ; Rodembusch, Fabiano Severo ^[1]

Afiliação do(s) autor(es)

^[1] Univ Fed Rio Grande do Sul, Grp Pesquisa Fotoquim Organ Aplicada, Inst Quim, Ave Bento Goncalves 9500, BR-91501970 Porto Alegre, RS - Brazil

^[2] Univ Estadual Campinas, Chem Inst, Rua Sergio Buarque de Holanda S-N, Poste Code 6154, BR-13083970 Campinas, SP - Brazil

^[3] Polish Acad Sci, Inst Phys, Al Lotnikow 32-46, PL-02668 Warsaw - Poland

• Tipo de documento: Artigo Científico
• Fonte: PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES; v. 17, n. 2, p. 231-238, FEB 2018.
• Citações Web of Science: 8

Resumo

This work presents the determination of acidic strengths at the electronic ground and excited states (pK(a) and pK{*}(a)) of three flavonol derivatives using electronic absorption and fluorescence emission spectroscopy. The differences of the pK(a) and pK{*}(a) values were successfully correlated with the molecular structures according to the substitution pattern at the flavonol structure (hydrogen, diethylamino or fluoro moieties). In order to obtain more information about the observed photoacidity of these super-acids, geometry optimizations and excitation energy calculations were performed at the CAM-B3LYP/6-311++ G(d, p) level for their neutral, protonated and deprotonated species. (AU)

• Processo FAPESP: 13/16245-2 - Propriedades fotofísicas de filmes finos de polímeros conjugados
• Beneficiário: Teresa Dib Zambon Atvars
• Modalidade de apoio: Auxílio à Pesquisa - Regular