title: Fluorescence properties and dipole moments of novel fused thienobenzofurans. Solvent and structural effects.
abstract: The electronic absorption, fluorescence excitation and emission spectra, and fluorescence quantum yields of novel fused thienobenzofurans, including thieno[3,2-b][1]benzofuran (1), [1]benzothieno[3,2-b]furan (2), and [1]benzothieno[3,2-b][1]benzofuran (3), were recorded in fourteen solvents of different polarities at room temperature. Compound 2 was not fluorescent. Experimental ground-state dipole moments of compounds 1-3 were measured in benzene at 298 K and compared with the corresponding theoretical dipole moment values. The solvent effects on the electronic absorption and fluorescence spectra of these thienobenzofurans were quantitatively investigated by means of solvatochromic correlations based on the Kawski-Chamma-Viallet and McRae equations. A weak negative solvatochromic behavior was found for these compounds, showing that their dipole moments are slightly lower in the excited singlet-state than in the ground-state. Kamlet-Abboud-Taft multiparameter relationships were also established for electronic absorption and fluorescence wavenumbers, and fluorescence quantum yields in most solvents, demonstrating the occurrence of specific solute-solvent interactions.
authors.affiliation: Laboratoire Géomatériaux et Environnement, EA 4119, Université Paris-Est Marne-la-Vallée, Marne la Vallée, France. jeanjacquesaaron@yahoo.fr
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Aaron
authors.forename: Cyril
authors.initials: C
authors.lastname: Párkányi
authors.forename: Alain
authors.initials: A
authors.lastname: Adenier
authors.forename: Caroline
authors.initials: C
authors.lastname: Potin
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Zajíčková
authors.forename: Omar R
authors.initials: OR
authors.lastname: Martínez
authors.forename: Jiří
authors.initials: J
authors.lastname: Svoboda
authors.forename: Pavel
authors.initials: P
authors.lastname: Pihera
authors.forename: Petr
authors.initials: P
authors.lastname: Váchal
mesh_terms: D001572:Benzofurans / Q000737:chemistry*; D005453:Fluorescence; D015394:Molecular Structure; D011789:Quantum Theory; D012997:Solvents / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001572:Benzofurans; D012997:Solvents