通过真空紫外光时间分辨光电子成像探测 NH 里德堡态的电子和振动弛豫动力学。

Electronic and vibrational relaxation dynamics of NH Rydberg states probed by vacuum-ultraviolet time-resolved photoelectron imaging.

机构信息

Laboratory for Physical Chemistry, ETH Zürich, Vladimir-Prelog-Weg 2, 8093 Zürich, Switzerland.

出版信息

J Chem Phys. 2019 Sep 14;151(10):104306. doi: 10.1063/1.5116707.

Abstract

Time-resolved dynamics of high-lying Rydberg states of ammonia (NH) prepared by using a vacuum ultraviolet (VUV) pump (∼9.3 eV) and an ultraviolet (UV) probe (∼4.7 eV) pulse are reported using photoelectron imaging detection. After photoexcitation, two main features appear in the photoelectron spectrum with vertical binding energies of ∼1.8 eV and ∼3.2 eV and with distinctly different anisotropy parameters β of ∼1.3 and ∼0.7, respectively. This information allows the unambiguous assignment of the respective Rydberg states and disentangles the induced electronic and vibrational dynamics. The combination of velocity-map imaging with femtosecond VUV and UV pulses is shown to offer an attractive approach for studying the dynamics of high-lying Rydberg states of small molecules.

摘要

采用真空紫外（VUV）泵（约 9.3 eV）和紫外（UV）探针（约 4.7 eV）脉冲制备的氨（NH）高里德堡态的时间分辨动力学，通过光电子成像检测进行了报道。光激发后，在光电子能谱中出现两个主要特征，垂直结合能分别约为 1.8 eV 和 3.2 eV，各向异性参数 β 分别约为 1.3 和 0.7，具有明显不同的特征。这些信息允许对各自的里德堡态进行明确的分配，并阐明诱导的电子和振动动力学。事实证明，飞秒 VUV 和 UV 脉冲的速度映射成像的结合为研究小分子的高里德堡态动力学提供了一种有吸引力的方法。