Photoinduced Electron Transfer From Carbazole to Halomethanes in a Gas Phase |
| |
Authors: | G A Zalesskaya E G Sambor N N Belyi |
| |
Institution: | (1) Institute of Molecular and Atomic Physics, National Academy of Sciences of Belarus, 70 Skorina Ave., Minsk, 220072, Belarus |
| |
Abstract: | Intermolecular photoinduced electron transfer (PET) in a gas phase was studied using carbazole vapor fluorescence quenching by halomethanes (CHCl3, CH2Br2, CCl4, CHBr3). The fluorescence quenching rate constants k
q changing from 2.3·105 sec–1·torr–1 in mixtures with CHCl3 to 4.6·106 sec–1·torr–1 in mixtures with CHBr3 at a constant temperature of 403 K were estimated. The dependence of the carbazole fluorescence decay rates in the presence of halomethanes on the free energy change G during transfer of the electron from carbazole to halomethanes is considered. It is suggested to take into account the influence of the vibrational energy of the carbazole molecule E
vib and its temperature changes in estimation of the G values. The differences between PET in the gas and liquid phases were analyzed. It is found that for mixtures with CCl4 and CHBr3 the negative temperature dependence of k
q is observed, when the decay rates and efficiencies of the intermolecular PET decreased with temperature increase in the range 403–573 K, i.e. these mixtures the electron transfer is not a barrier-restricted process. |
| |
Keywords: | carbazole halomethanes time-resolved carbazole fluorescence fluorescence quenching gas phase intermolecular photoinduced electron transfer temperature dependence of the efficiency of photoinduced electron transfer |
本文献已被 SpringerLink 等数据库收录! |
|