乙、丙苯的ν_(12)环振动的皮秒时间分辨CARS研究

Picosecond Time-resolved CARS Studies of v_(12) Ring-stretching Vibration of Ethyl-and Propyl-Bbenzenes

在室温下，使用皮秒时间分辨ＣＡＲＳ测量了乙、丙苯的ν１２环振动模的退相动力学．观察到了正 丙苯的两种构像的ν１２模的不同退相行为 乙苯和异丙苯的ν１２模的退相服从单指数衰减，而正丙苯的ν１２环 模的退相却是振荡衰减的．这种振荡衰减被归咎于正丙苯的ｔｒａｎｓ和ｇａｕｃｈｅ构像的ν１２环振动模之间的量子 拍．乙、丙苯的ν１２环振动模的退相时间常数被给出，并极大地受烷基链的构像、结构和长度的影响．

the dephasing dynamics of ν12 ring -stretching modes of ethyl- and propyl- benzenes are measured using picosecond time-resolved CARS at room temperature. The different dephasing behaviors of ν 12 modes of two conformations of n-propylbenzene are observed for the first time. The single exponential dephasing decay profiles are obtained for theν 12 modes of the ethyl- and isopropyl- benzenes while the oscillation is observed in the dephasing dynamics of the ν12 mode of n-propylbenzene and is attributed to the quantum beat between the ν12 modes of trans and gauche conformers of n-propylbenzene. The dephasing tune constants of the ν 12 modes are given and influenced greatly by the length, comformation and structure of alkyl chains.