Acta Phys. -Chim. Sin. ›› 2011, Vol. 27 ›› Issue (04): 971-976.doi: 10.3866/PKU.WHXB20110421

• PHOTOCHEMISTRY AND RADIATION CHEMISTRY • Previous Articles     Next Articles

Transient Absorption Spectroscopy of the Effects of the Ionic Liquid [bmim][BF4] on the Photochemical Reactions of Benzil

ZHU Guang-Lai1, WU Guo-Zhong2, CUI Zhi-Feng1, XU Xin-Sheng1   

  1. 1. Institute of Atomic and Molecular Physics, Anhui Normal University, Wuhu 241000, Anhui Province, P. R. China;
    2. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China
  • Received:2010-11-01 Revised:2010-12-20 Published:2011-03-29
  • Contact: ZHU Guang-Lai, WU Guo-Zhong;
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (20673137, 20903004), Science Foundation of the Education Committee of Anhui Province, China (KJ2010A145) and Scientific Research Starting Foundation for Teachers with Ph.D. in Anhui Normal University, China.


Using benzil (BZ) as a probe molecule, the photochemical properties of the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) and its binary mixed solutions with acetonitrile (MeCN) were investigated by nanosecond laser photolysis. We found that the decay of the triplet excited state of benzil (3BZ*) in a N2-saturated solution followed mono-exponential kinetics. Along with the increase in the volume fraction (VIL) of [bmim][BF4] in the mixed solvents, the absorption peak of 3BZ* did not change. However, the effect of different VIL values on the photoinduced electron transfer process in the mixture of [bmim][BF4]/MeCN was obvious. Moreover, the apparent rate constant (kgr) of the formed radical decreased obviously with an increase in VIL. When the ratio of [bmim][BF4] was sufficiently high, the electron transfer reaction between 3BZ* and triethylamine or N,N,N′,N′-tetramethyl-p-phenylenediamine was retarded.

Key words: Room temperature ionic liquid, 1-Butyl-3-methylimidazolium tetrafluoroborate, Benzil, Laser photolysis, Photoinduced electron transfer


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