title: Synthesis, electrochemical, and optical properties of new fluorescent, substituted thieno[3,2-b][1]benzothiophenes.
abstract: The synthesis, electrochemical and optical properties of three fluorescent substituted thieno[3,2-b][1]benzothiophenes (TBT) derivatives, including 3-methoxythieno[3,2-b][1]benzothiophene (3-MeO-TBT), 2,3-dimethylthieno[3,2-b][1]benzothiophene (2,3-diMe-TBT), and 6-methoxythieno[3,2-b][1]benzothiophene-2-carboxylate (6-MeO-TBT-2-COOMe), were investigated. The oxidation potential values varied between 1.40 and 1.20 V/SCE according to the electronic substituent effect, and electropolymerization attempts, performed in 0.1 M LiClO(4) acetonitrile solution, led to the formation of very thin films of poly(3-MeO-TBT) and poly(2,3-di-Me-TBT). Electronic absorption spectra, fluorescence excitation and emission spectra, fluorescence quantum yields (Φ(F)) , lifetimes (τ(F)), and other photophysical parameters of the three new TBT derivatives were measured in DMSO solutions at room temperature. For the methyl-and methoxy-substituted TBT derivatives, the fluorescence emission peak were slightly red shifted relative to that of unsubstituted TBT (Δλ(em) = 1-12 nm) whereas, in the case of 6-MeO-TBT-2-COOMe, a rather strong red-shift (Δλ(em) = 73 nm) was attributed to the existence of a "push-pull" electronic interaction of the MeO and COOMe groups. All Φ(F) values were rather high, varying between 0.11 and 0.35, according to the substituent effect. Fluorescence decays were mono-exponential and τ(F) values were very short, ranging between 0.11 and 0.30 ns for the substituted TBT derivatives until study.
authors.affiliation: Laboratoire ITODYS, associé au CNRS UMR 7086, Université Paris Diderot, Paris 7, 15, rue Jean de Baïf, 75205, Paris Cedex 13, France.
authors.forename: Cheikh
authors.initials: C
authors.lastname: Lô
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Aaron
authors.forename: Václav
authors.initials: V
authors.lastname: Kozmík
authors.forename: Jirí
authors.initials: J
authors.lastname: Svoboda
authors.forename: Jean-Claude
authors.initials: JC
authors.lastname: Brochon
authors.forename: Li
authors.initials: L
authors.lastname: Na
mesh_terms: D000042:Absorption; D002627:Chemistry, Physical; D004563:Electrochemistry; D005453:Fluorescence; D015394:Molecular Structure; D055620:Optical Phenomena; D010084:Oxidation-Reduction; D012996:Solutions / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D013876:Thiophenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D012996:Solutions; D013876:Thiophenes; C088015:benzothiophene
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