Photophysical properties of coumarin compounds in neat and binary solvent mixtures: evaluation and correlation between solvatochromism and solvent polarity parameters

Autor(es)

Leonardo M. Moreira ^[1] ; Mirian M. de Melo ^[2] ; Priscila A. Martins ^[2] ; Juliana P. Lyon ^[3] ; Ana Paula Romani ^[4] ; Lúcia Codognoto ^[6] ; Sandra C. dos Santos ^[6] ; Hueder P. M. de Oliveira ^[7]

Afiliação do(s) autor(es)

^[1] Univ Fed Sao Joao Del Rei UFSJ, Dept Zootecnia DEZOO, BR-36301360 Sao Joao Del Rei, MG - Brazil

^[2] Univ Vale Paraiba UNIVAP, Inst Pesquisa & Desenvolvimento, Sao Jose Dos Campos, SP - Brazil

^[3] Univ Fed Sao Joao Del Rei UFSJ, Dept Ciencias Nat DCNAT, BR-36301160 Sao Joao Del Rei, MG - Brazil

^[4] Univ Fed ABC, Ctr Engn Modelagem & Ciencias Sociais Aplicadas, BR-09210580 Santo Andre, SP - Brazil

^[5] Universidade Federal de São Paulo. Departamento de Ciências Exatas e da Terra - Brasil

^[6] Univ Fed Pelotas UFPel, Ctr Ciencias Quim Farmaceut & Alimentos, BR-96160000 Pelotas, RS - Brazil

^[7] Univ Fed ABC, Ctr Ciencias Nat & Humanas, BR-09210170 Santo Andre, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of the Brazilian Chemical Society; v. 25, n. 5, p. 873-881, 2014-05-00.

Resumo

This work studied the fluorescent and solvatochromic properties of coumarin and its derivatives aiming to contribute in the elucidation of the excited state behavior of the molecule in solvent mixtures. This approach has been developed through a set of measurements involving different solvent ratios, which present distinct dielectric constants. The excitation and fluorescence maxima were largely blue-shifted with increasing participation of the organic solvent and the Stokes shifts were unusually low in mixtures with lower solvent polarity parameter, Δf. The emission intensity of coumarin was extremely sensitive to the polarity and the different structural conformations of solvents. These results influenced the spectroscopic behavior and explain the deviation from the linearity of the Lippert-Mataga relationship. The use of fluorescence spectroscopy makes the understanding of the behavior of the systems studied when in the presence of different environments being extremely important for the identification and characterization of coumarin in different pharmaceutical formulations. (AU)

• Processo FAPESP: 06/56701-3 - Estudo de processos de agregacao em moleculas com potencial aplicacao em terapia fotodinamica.
• Beneficiário: Hueder Paulo Moisés de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 08/50588-6 - Eletrodos de ouro modificados por monocamadas auto-organizadas aplicados à determinação de pesticidas
• Beneficiário: Lucia Codognoto de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular