Photoinduced intramolecular electron transfer of fluorescein and violgen, carbazole

• Published in: Science China. Chemistry Vol. 40; no. 5; pp. 449 - 456
• Main Author: 张宏 张曼华 沈涛
• Format: Journal Article
• Language: English
• Published: Heidelberg Springer Nature B.V 01.10.1997
• Subjects: carbazole; Carbazoles; Efficiency; electron; Electron transfer; Emission analysis; Emission spectra; Fluorescein; Fluorescence; Free energy; intramolecular; Quenching; transfer; violgcn
• ISSN: 1674-7291; 1006-9291; 1869-1870; 1862-2771
• DOI: 10.1007/BF02875412

A series of polyads consisting of covalently-(CH2)4-linked fluorescein with carbazole and violger.Live been synthesized and characterized The studies of absorption,emission spectra and fluorescence lifetime quenching indicated that the intramolecular fluorescence quenching of fluorescein by violgen is mainly a static process through the formation of non emission complex (fluorescence quenching efficiency φQ=0.97,lifetime quenching efficiency φH 0,quenching efficiency of formation of non-emission complex φC=0.97); while the quenching by carbazole is mainly a dynamic electron transfer process (φQ=0.63,φET=0.63,φC=0).In the violgen-fluorescein-carbazole triads,φQ=0.97,Q ET=0.65,φC=0.32,which suggests that the photoinduced interaction of fluorescein-carbazole pair and that of violgen-fluorescein pair are in a competitive process,the dynamic electron transfer from carbazole to fluorecein is dominant in the process The free energy change of the photoinduced electron transfer and the back reac-tiorns i