TY - JOUR
T1 - One- and two-photon photochemical stability of linear and branched fluorene derivatives
AU - Corredor, Claudia C.
AU - Belfield, Kevin D.
AU - Bondar, Mykhailo V.
AU - Przhonska, Olga V.
AU - Yao, Sheng
N1 - Funding Information:
We wish to acknowledge the U.S. Civilian Research and Development Foundation (UK-C2-2574-MO-04), the donors of The Petroleum Research Fund of the American Chemical Society, the Research Corporation Cottrell College Science program, the National Research Council COBASE award, the Florida Hospital Gala Endowed Program for Oncologic Research, the National Science Foundation (ECS-0217932 and DMR-9975773), and the University of Central Florida Presidential Initiative for Major Research Equipment for partial support of this work.
PY - 2006/11/15
Y1 - 2006/11/15
N2 - Photochemical decomposition of the fluorene derivatives, 4,4′-[[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl]bis(N,N-diphenyl)benzeneamine (1) and 4,4′,4″-[[9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2,1-ethenediyl]tris(N,N-diphenyl)benzeneamine (2), were investigated in pTHF under one- (UV-lamp) and two-photon (femtosecond laser) excitation. The quantum yields of the photoreactions were determined by absorption and fluorescence methods in air-saturated and deoxygenated solutions. The values of quantum yields were in the range (1.5-2.1) × 10-6 for both types of irradiation, indicating that similar photobleaching processes occur under both one- and two-photon excitation. Deoxygenation of pTHF increased photostability of 1 and 2 by over an order of magnitude relative to air-saturated solutions. A cursory examination of some of the photochemical products (analyzed by HPLC and APCI-MS spectroscopy techniques) revealed an important role of ground state oxygen in the photoreactions, since no oxidation products were observed upon irradiation in the presence of the well know singlet oxygen sensitizer methylene blue.
AB - Photochemical decomposition of the fluorene derivatives, 4,4′-[[9,9-bis(ethyl)-9H-fluorene-2,7-diyl]di-2,1-ethenediyl]bis(N,N-diphenyl)benzeneamine (1) and 4,4′,4″-[[9,9-bis(ethyl)-9H-fluorene-2,4,7-triyl]tri-2,1-ethenediyl]tris(N,N-diphenyl)benzeneamine (2), were investigated in pTHF under one- (UV-lamp) and two-photon (femtosecond laser) excitation. The quantum yields of the photoreactions were determined by absorption and fluorescence methods in air-saturated and deoxygenated solutions. The values of quantum yields were in the range (1.5-2.1) × 10-6 for both types of irradiation, indicating that similar photobleaching processes occur under both one- and two-photon excitation. Deoxygenation of pTHF increased photostability of 1 and 2 by over an order of magnitude relative to air-saturated solutions. A cursory examination of some of the photochemical products (analyzed by HPLC and APCI-MS spectroscopy techniques) revealed an important role of ground state oxygen in the photoreactions, since no oxidation products were observed upon irradiation in the presence of the well know singlet oxygen sensitizer methylene blue.
KW - Fluorene photostability
KW - Photobleaching
KW - Photodecomposition
KW - Two-photon absorption
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U2 - 10.1016/j.jphotochem.2006.03.036
DO - 10.1016/j.jphotochem.2006.03.036
M3 - Article
AN - SCOPUS:33749517311
SN - 1010-6030
VL - 184
SP - 105
EP - 112
JO - Journal of Photochemistry and Photobiology A: Chemistry
JF - Journal of Photochemistry and Photobiology A: Chemistry
IS - 1-2
ER -