论文部分内容阅读
结合飞秒时间分辨的质谱技术与时间分辨的光电子影像技术对苯S2激发态的超快动力学进行了研究.苯分子吸收两个400 nm的光子被激发到S2态,之后再用一个267 nm的光子对其进行探测.获得的母体离子产率随泵浦探测时间延迟的变化曲线包含了两个不同的时间寿命组分.第一个时间寿命组分(90±1)fs被归纳为S2态到S1/S0态的内转换过程;第二个时间寿命组分(5.0±0.2)ps被归纳为S1态的衰减过程.实验中观察到的第二个寿命组分小于早前的研究结果,这表明了在S1态的衰减过程中还可能存在其他的过程.从时间分辨的光电子影像提取得到的光电子能谱中发现了一个新的失活过程,该过程被归结为激发态S1的振动态与“热”三重态T3之间的系间交叉过程.
The fast kinetics of the excited state of benzene S2 was studied by combining the femtosecond time-resolved mass spectrometry with the time-resolved photoelectron imaging technique. The absorption of two 400 nm photons by benzene molecules was excited to the S2 state, followed by a 267 nm Of the photon to detect the precursor ion yield obtained with the pump probe time delay curve contains two different life components.At the first time life components (90 ± 1) fs are summarized as S2 State to the S1 / S0 state, and the second life component (5.0 ± 0.2) ps is reduced to the decay of S1 state.The second life component observed in the experiment is smaller than the previous one , Indicating that there may be other processes during the decay of the S1 state.A new deactivation process is found in the photoelectron spectra extracted from the time-resolved photoelectron imaging, and the process is attributed to the oscillation of the excited state S1 Dynamic and “hot” triplet T3 between the Department of cross-process.