Ultrafast excited-state dynamics of 2,4-dimethylpyrrole
Ultrafast excited-state dynamics of 2,4-dimethylpyrrole
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2,4-二甲基吡咯的超快激发态动力学
DOI：
10.1039/c7cp06292c
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发表时间：
2017
影响因子：
3.3
通讯作者：
Yang Xueming
中科院分区：
文献类型：
--
作者：
Yang Dongyuan;Chen Zhichao;He Zhigang;Wang Hengding;Min Yanjun;Yuan Kaijun;Dai Dongxu;Wu Guorong;Yang Xueming
用时间分辨光电子成像方法研究了2，4-二甲基吡咯在255.8-199.7 nm波长范围内激发后的超快激发态动力学。结果表明，在较长波长（255.8，250.0，246.0和242.0nm）的激发下，S1（1πσ*）态的布居数在30 fs内衰减出光电离窗口.在237.7 nm处，第二个1πσ* 态被激发，其在约130 fs内衰减。在较短的泵浦波长（231.8，224.8，217.5和199.7 nm），分配不太明确。我们尝试性地将初始光激发态归属于1π 3 p里德堡态，它的衰变时间约为60 fs，其中S1（1πσ*）态的内转换是衰变通道之一。这些1π 3 p里德堡态的寿命随泵浦波长的变化很小。
The ultrafast excited-state dynamics of 2,4-dimethylpyrrole following excitation at wavelengths in the range of 255.8–199.7 nm are studied using the time-resolved photoelectron imaging method. It is found that excitation at longer wavelengths (255.8, 250.0, 246.0 and 242.0 nm) results in population of the S1(1πσ*) state, which decays out of the photoionization window in less than 30 fs. At 237.7 nm, the second 1πσ* state is excited, which decays in about 130 fs. At shorter pump wavelengths (231.8, 224.8, 217.5 and 199.7 nm), the assignments are less clear-cut. We tentatively assign the initially photoexcited states to the 1π3p Rydberg states, which decay in about 60 fs, with internal conversion to the S1(1πσ*) state as one of the decay channels. The lifetimes of these 1π3p Rydberg states vary little with the pump wavelengths in this wavelength range.