title: An experimental study of the electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles and their electrosynthesized polymers.
abstract: Electronic absorption and fluorescence spectral properties of new p-substituted-N-phenylpyrroles (N-PhPys), including HOPhPy, MeOPhPy, ThPhPy, PhDPy, DPhDPy, PyPhThThPhPy, and their available, electrosynthesized polymers were investigated. Electronic absorption spectra, fluorescence excitation and emission spectra, fluorescence quantum yields (ΦF) and lifetimes (τF), and other photophysical parameters of these N-PhPy derivatives and their polymers were measured in DMF, DMSO diluted solutions and/or solid state at room temperature. The electronic absorption spectra of N-PhPy derivatives and their polymers included one to several bands, located in the 270-395 nm region, according to the p-phenyl substituent electron-donating effect and conjugated heteroaromatic system length. The fluorescence excitation spectra were characterized by one broad main peak, with, in most cases, one (or more) poorly resolved shoulder (s), appearing in the 270-405 nm region, and their emission spectra were generally constituted of several bands located in the 330-480 nm region. No significant shift of the absorption, fluorescence excitation and emission spectra wavelengths was found upon going from the monomers to the corresponding polymers. ΦF values were high, varying between 0.11 and 0.63, according to the nature of substituents(s) and to the conjugated system extension. Fluorescence decays were mono-exponential for the monomers and poly-exponential for PyPhThThPhPy and for polymers. τF values were relatively short (0.35-5.17 ns), and markedly decreased with the electron-donor character of the phenyl group p-substituent and the conjugated system extension.
authors.affiliation: Laboratoire de Chimie Physique Organique et d'Analyse Instrumentale, Département de Chimie, Faculté des Sciences, Université Cheikh Anta Diop, BP 5005 Dakar-Fann, Senegal.
authors.forename: A K D
authors.initials: AK
authors.lastname: Diaw
authors.affiliation: Laboratoire de Chimie Physique Organique et d'Analyse Instrumentale, Département de Chimie, Faculté des Sciences, Université Cheikh Anta Diop, BP 5005 Dakar-Fann, Senegal.
authors.forename: D
authors.initials: D
authors.lastname: Gningue-Sall
authors.affiliation: LPICM (UMR 7647), Ecole Polytechnique, Route de Saclay, 91128 Palaiseau, France.
authors.forename: A
authors.initials: A
authors.lastname: Yassar
authors.affiliation: LBPA-CNRS UMR 8113, ENS Cachan, 61 Av Président Wilson, 94235 Cachan, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Brochon
authors.affiliation: LBPA-CNRS UMR 8113, ENS Cachan, 61 Av Président Wilson, 94235 Cachan, France.
authors.forename: E
authors.initials: E
authors.lastname: Henry
authors.affiliation: Laboratoire Géomatériaux et Environnement (LGE), Université Paris-Est Marne-la-Vallée, 5 Bd Descartes, Champs-sur-Marne, 77454 Marne la Vallée Cedex 2, France. Electronic address: jeanjacquesaaron@yahoo.fr.
authors.forename: J-J
authors.initials: JJ
authors.lastname: Aaron
mesh_terms: D004563:Electrochemistry; D004583:Electrons; D008958:Models, Molecular; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry*; D011758:Pyrroles / Q000737:chemistry*; D011789:Quantum Theory; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature
chemical_list: D011108:Polymers; D011758:Pyrroles; C517402:N-phenylpyrrole
keywords: Electronic absorption spectra; Fluorescence spectra; Photophysical properties; Poly(N-Ph-Py)s; p-Substituted N-phenylpyrrroles (N-Ph-Pys)