Heim Pascal, Mai Sebastian, Thaler Bernhard, Cesnik Stefan, Avagliano Davide, Bella-Velidou Dimitra, Ernst Wolfgang E, González Leticia, Koch Markus
Institute of Experimental Physics , Graz University of Technology , Petersgasse 16 , A-8010 Graz , Austria.
Institute of Theoretical Chemistry, Faculty of Chemistry , University of Vienna , Währinger Str. 17 , A-1090 Vienna , Austria.
J Phys Chem Lett. 2020 Feb 20;11(4):1443-1449. doi: 10.1021/acs.jpclett.9b03462. Epub 2020 Feb 6.
The response of a molecule to photoexcitation is governed by the coupling of its electronic states. However, if the energetic spacing between the electronically excited states at the Franck-Condon window becomes sufficiently small, it is infeasible to selectively excite and monitor individual states with conventional time-resolved spectroscopy, preventing insight into the energy transfer and relaxation dynamics of the molecule. Here, we demonstrate how the combination of time-resolved spectroscopy and extensive surface hopping dynamics simulations with a global fit approach on individually excited ensembles overcomes this limitation and resolves the dynamics in the n3p Rydberg states in acetone. Photoelectron transients of the three closely spaced states n3p, n3p, and n3p are used to validate the theoretical results, which in turn allow retrieving a comprehensive kinetic model describing the mutual interactions of these states for the first time.
分子对光激发的响应由其电子态的耦合决定。然而，如果在弗兰克 - 康登窗口处电子激发态之间的能量间距变得足够小，那么用传统的时间分辨光谱选择性地激发和监测单个态是不可行的，这阻碍了对分子能量转移和弛豫动力学的深入了解。在这里，我们展示了时间分辨光谱与广泛的表面跳跃动力学模拟相结合，并采用全局拟合方法处理单个激发的系综，如何克服这一限制并解析丙酮中 n3p 里德堡态的动力学。三个紧密间隔的态 n3p、n3p 和 n3p 的光电子瞬态用于验证理论结果，这反过来又首次允许检索一个描述这些态相互作用的综合动力学模型。
