酞菁锌分子激发态的超快内转换和振动弛豫  

Ultrafast Investigation of the Internal Conversion and Vibrational Relaxation in Excited States of Zinc Phthalocyanine Derivatives*

作　　者：王朝晖[1] 衷庆华[1] 熊轶嘉[1] 孙亚 孔繁敖[1] 

机构地区：[1]中国科学院化学研究所分子反应动力学国家重点实验室

出　　处：《Chinese Journal of Chemical Physics》1998年第1期15-19,共5页化学物理学报（英文）

基　　金：国家自然基金

摘　　要：用飞秒时间分辨荧光亏蚀法研究了四特丁基酞菁（ＢｕＰｃ）、四特丁基酞菁锌（ＺｎＢｕＰｃ）和四丙氧基酞菁锌（ＺｎＰｒＰｃ）激发态的超快驰豫过程。用波长为３９８ｍｍ和７９６ｍｍ的超短脉冲激光激发分子，观察了Ｓ２态到Ｓ１态的内转换，其特征时间约为３０ｆｓ。在７９６ｍｍ先于３９８ｍｍ作用于样品分子时，观察到了荧光强度渐变的过程，通过分析认为这一过程反映了Ｓ１的振动驰豫。通过对实验数据的拟合，得到了它们的振动驰豫特征时间，ＢｕＰｃ分子为１．５ｐｓ，ＺｎＢｕＰｃ和ＺｎＢｕＰｃ的特征时间分别为１３．４和７．６ｐｓ。An internal conversion(IC)process from the S2 state to the S1 state of tetratertbutylphthalocyanine(BuPc),Zinc tetratertbutylphthalocyanine(ZnBuPc)and Zinc tetratpropoxyphthalocyanine(ZnPrPc)has been investigated respectively using femtosecond timeresolved fluorescence depletion methodThe S2 state of BuPc,ZnBuPc and ZnPrPc was prepared by the excitation of a 398nm laser pulse of 100fs durationVia a fast IC process from S2 to S1,the excited molecule emitted fluorescence from the S1 stateHowever,an ultrafast 796nm laser pulse depopulated the S2 state and therefore weakened the fluorescenceThe time scale of IC is estimated to be tens of femtosecondsThe vibrational relaxation in the S1 state was also studied by two 796nm photon excitation followed with a 398nm dumping laser pulseThe decay rate was measured as 15ps for BuPcFor ZnBuPc and ZnPrPc,decay rate of 134ps and 76ps were also observed respectively

关 键 词：飞秒时间分辨 酞菁锌 内转换 振动弛豫 激发态 

分 类 号：O614.241[理学—无机化学]