意大利米兰理工大学Nisoli, Mauro研究团队报道了光离给体-π-受体分子的飞秒电子转移动力学。相关研究成果发表在2024年9月25日出版的国际学术期刊《自然—化学》。

分子暴露于阿秒极紫外（XUV）脉冲中，为研究耦合电子-核动力学的早期阶段提供了一个独特的机会，其中不同自由度所起的作用超出了标准化学直觉。

研究人员从实验和理论上研究了原型供体-π-受体分子（即硝基苯胺）中，由快速电离引发的电荷转移过程的第一步。通过将阿秒XUV泵浦/飞秒红外探测光谱与先进的多体量子化学计算相结合，对这一过程进行了时间分辨测量。

研究发现，在低于10-fs的时间尺度上，核和电子的协同运动驱动了供体基团的电子转移。随后，由于在分子阳离子的激发电子态中探测到连续扩展的核波包，出现了亚30-fs的弛豫过程。这些发现揭示了电子-核耦合在供体-π-受体系统响应光电离时所起的作用。

附：英文原文

Title: Few-femtosecond electron transfer dynamics in photoionized donor–π–acceptor molecules

Author: Vismarra, Federico, Fernndez-Villoria, Francisco, Mocci, Daniele, Gonzlez-Vzquez, Jess, Wu, Yingxuan, Colaizzi, Lorenzo, Holzmeier, Fabian, Delgado, Jorge, Santos, Jos, Baares, Luis, Carlini, Laura, Castrovilli, Mattea Carmen, Bolognesi, Paola, Richter, Robert, Avaldi, Lorenzo, Palacios, Alicia, Lucchini, Matteo, Reduzzi, Maurizio, Borrego-Varillas, Roco, Martn, Nazario, Martn, Fernando, Nisoli, Mauro

Issue&Volume: 2024-09-25

Abstract: The exposure of molecules to attosecond extreme-ultraviolet (XUV) pulses offers a unique opportunity to study the early stages of coupled electron–nuclear dynamics in which the role played by the different degrees of freedom is beyond standard chemical intuition. We investigate, both experimentally and theoretically, the first steps of charge-transfer processes initiated by prompt ionization in prototype donor–π–acceptor molecules, namely nitroanilines. Time-resolved measurement of this process is performed by combining attosecond XUV-pump/few-femtosecond infrared-probe spectroscopy with advanced many-body quantum chemistry calculations. We show that a concerted nuclear and electronic motion drives electron transfer from the donor group on a sub-10-fs timescale. This is followed by a sub-30-fs relaxation process due to the probing of the continuously spreading nuclear wave packet in the excited electronic states of the molecular cation. These findings shed light on the role played by electron–nuclear coupling in donor–π–acceptor systems in response to photoionization.

DOI: 10.1038/s41557-024-01620-y

Source: https://www.nature.com/articles/s41557-024-01620-y