Full-Model VCD and AI-Assisted Interpretation: Unveiling New Chiral Phenomena in Atomically Precise Metal Clusters and Flexible Salen Ligands and Their Metal Complexes
Yunjie Xu 院士
加拿大阿尔伯塔大学
时间：2025年5月16日（星期五）15:00
地点：思明校区卢嘉锡楼202报告厅
翔安校区能源材料大楼3号楼会议室5、6（转播）
漳州校区生化主楼307教室（转播）
厦门大学谱学分析与仪器教育部重点实验室
2025年5月12日
报告人简介：
Yunjie Xu earned her BSc in Chemistry and in Applied Mathematics from Xiamen University and a PhD in Physical Chemistry from the University of British Columbia. She is a full professor at the University of Alberta and holds the Tier I Canada Research Chair in Chirality and Chirality Recognition. Xu's research program focuses on chirality recognition, transfer, and amplification events in isolated molecular clusters, condensed phases, and at liquid-liquid interfaces. Her pioneering contributions include quantifying stereospecific non-covalent interactions and untangling chiral events under resonance conditions, thereby advancing our understanding of chiral forces and the light-matter interactions responsible for intricate chiral phenomena. She has received numerous awards and honors, including the 2019 Gerhard Herzberg Award from Canadian Society for Analytical Sciences and Spectroscopy, the 2024 John C. Polanyi Award from Canadian Society for Chemistry, and 2024-2025 Killam Annual Professorship from the Killam Foundation. In 2018, she was elected to the Fellowship of the Royal Society of Canada, Academy of Science.
报告摘要：
Our research program centers on understanding mechanisms of chirality recognition, transfer, amplification at the molecular level. Two examples will be discussed in this presentation.
Built on the recent synthetic advances in ultrastable, chiral atomically precise metal clusters, we examine the vibrational circular dichroism (VCD) spectral patterns of four atomically-precise metal clusters with octahedral metal cores protected by monolayer organic ligands. While previous studies on atomically precise metal clusters have employed truncated models with fewer metal atoms and/or ligands to model chiroptical responses, we demonstrate that such approaches have critical deficiencies by using full-model VCD calculations. Furthermore, we develop a modified modes analysis to unveil the contribution of individual ligands, their collective arrangements and numbers, and the asymmetry of the metal core to the observed VCD enhancement.
In the second example, we illustrate how the conventional DFT approach—identify low-energy conformers and simulate their Boltzmann-averaged spectra—fails badly for a highly flexible Salen ligand in solution. Although it is well-known that solvents can severely affect conformational stability, accounting for these effects remains extremely challenging. We apply an AI-assisted approach to re-weight the contributions of individual conformers. I will discuss the working principle of this approach and present its applications on the Salen ligand and its transition metal complexes.