近日，瑞士日内瓦大学的Jean-Pierre Wolf&Yi-Ping Chang与瑞士苏黎世联邦理工学院的Hans Jakob Worner等人合作并取得一项新进展。经过不懈努力，他们揭示了锥形交叉点产生的电子动力学及其在水溶液中的退相干性。相关研究成果已于2024年11月27日在国际知名学术期刊《自然—物理学》上发表。

该研究团队利用X射线光谱学揭示了孤立和溶剂化吡嗪分子中，通过锥形交叉点诱导的电子弛豫所产生的电子动力学。研究表明，随后产生的动力学对应于芳香环周围电子结构的循环重排。此外，研究人员还发现，当吡嗪溶解在水中时，这种电子动力学被完全抑制。

这一观察结果证实，锥形交叉点可以产生并非直接由泵浦脉冲激发的电子动力学，并且水溶剂化可以在不到40飞秒的时间内使其失去相干性。这些结果对研究光诱导分子动力学过程中产生的电子动力学具有重要意义，并揭示了它们对水溶剂化的敏感性。

据悉，分子电子结构的动力学重排可能由核运动、电子相干性或电子关联性等不同现象驱动。记录这种电子动力学过程并确定其在水溶液中的演变一直是个挑战。

附：英文原文

Title: Electronic dynamics created at conical intersections and its dephasing in aqueous solution

Author: Chang, Yi-Ping, Balciunas, Tadas, Yin, Zhong, Sapunar, Marin, Tenorio, Bruno N. C., Paul, Alexander C., Tsuru, Shota, Koch, Henrik, Wolf, Jean-Pierre, Coriani, Sonia, Wrner, Hans Jakob

Issue&Volume: 2024-11-27

Abstract: A dynamical rearrangement in the electronic structure of a molecule can be driven by different phenomena, including nuclear motion, electronic coherence or electron correlation. Recording such electronic dynamics and identifying its fate in an aqueous solution has remained a challenge. Here, we reveal the electronic dynamics induced by electronic relaxation through conical intersections in both isolated and solvated pyrazine molecules using X-ray spectroscopy. We show that the ensuing created dynamics corresponds to a cyclic rearrangement of the electronic structure around the aromatic ring. Furthermore, we found that such electronic dynamics were entirely suppressed when pyrazine was dissolved in water. Our observations confirm that conical intersections can create electronic dynamics that are not directly excited by the pump pulse and that aqueous solvation can dephase them in less than 40fs. These results have implications for the investigation of electronic dynamics created during light-induced molecular dynamics and shed light on their susceptibility to aqueous solvation.

DOI: 10.1038/s41567-024-02703-w

Source: https://www.nature.com/articles/s41567-024-02703-w