Acta Phys. -Chim. Sin. ›› 2007, Vol. 23 ›› Issue (07): 1127-1130.doi: 10.3866/PKU.WHXB20070732

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Laser Flash Photolysis of C60-dexamethasone

LIU Rui-Li; ZHAO Hong-Wei; ZHANG Zhao-Xia; YAO Si-De; LI Qing-Nuan; LI Wen-Xin   

  1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, P. R. China
  • Received:2007-01-23 Revised:2007-03-14 Published:2007-07-03
  • Contact: LI Wen-Xin E-mail:liwenxin@sinap.ac.cn

Abstract: Laser flash photolysis technique was employed to characterize the triplet excited state behavior of C60-dexamethasone (C60-DE) in benzene. The time-resolved triplet-triplet (T-T) difference absorption spectrum of 3C60-DE* with optical excitation (355 nm laser pulse) was recorded. The spectrum of 3C60-DE* exhibited maxima at 700, 440, 350, and 310 nm. The bleaching maximum observed at 330 nm coincides well with the ground-state maximum in this region. 3C60-DE* could be quenched by oxygen. Compared with 3C60*, the T-T annihilation rate constant of 3C60-DE* deduced ((5.03±1.31)×109 L·mol-1·s-1 for 3C60* and (3.53±0.87)×109 L·mol-1·s-1 for 3C60-DE*), and the life time of 3C60-DE*increased ((12.0±2.6) μs for 3C60*, (18.0±3.3) μs for 3C60-DE*). The reason may be that the connection of dexamethasone decreased the colliding probability of the C60 ball.

Key words: C60-dexamethasone, Laser flash photolysis, Excited triplet state, Annihilation rate constant, Triplet lifetime

MSC2000: 

  • O644.18