title: Synthesis and spectral characteristics of two novel intramolecular charge transfer fluorescent dyes.
abstract: The synthesis and absorption/fluorescence properties of two novel intramolecular charge transfer (ICT) compounds of (fluorene-2-yl)-(9-ethylcarbazole-3-yl) ketene and 1-phenyl-3-(fluorenone-2-yl)-5-(9-ethylcarbazole-3-yl)-2-pyrazoline were reported. The primary structure of the target compounds was characterized by IR and (1)H NMR. The systems contained a fluorenone or a propenon group as an electron acceptor (A) and an N-ethylcarbazole and a pyrazoline group as electron donors (D). From the emissive properties it was concluded that the electronic coupling between D and A was sufficient to allow charge transfer in these molecules. The ICT maximal emission displayed a large wavelength shift and Stokes shifts increased in response to the increase of the solvent polarity. The highly solvatochromic properties made the two compounds of great interest as new classes of fluorescent probes, electroluminescent and electrofax materials.
authors.affiliation: Research Center of Environmental Science and Engineering, Department of Chemistry, Shanxi University, Shanxi 030006, PR China.
authors.forename: Shengmei
authors.initials: S
authors.lastname: Song
authors.forename: Dong
authors.initials: D
authors.lastname: Ju
authors.forename: Junfen
authors.initials: J
authors.lastname: Li
authors.forename: Duxin
authors.initials: D
authors.lastname: Li
authors.forename: Yanli
authors.initials: Y
authors.lastname: Wei
authors.forename: Chuan
authors.initials: C
authors.lastname: Dong
authors.forename: Peihua
authors.initials: P
authors.lastname: Lin
authors.forename: Shaomin
authors.initials: S
authors.lastname: Shuang
mesh_terms: D004583:Electrons; D005030:Ethylenes; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry; D007659:Ketones; D011720:Pyrazoles; D012997:Solvents; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D005030:Ethylenes; D005456:Fluorescent Dyes; D007659:Ketones; D011720:Pyrazoles; D012997:Solvents; C008223:ketene