近日，中国科学院福建物质结构研究所郭国聪团队研究了原位光差电子密度揭示的发光聚集体中准分子的非常规构型。2025年12月17日，《结构化学》杂志发表了这篇成果。

激基缔合物在自然界与现代工业应用中扮演着重要角色；然而，由于难以原位观测其形成过程，人们对其构型的精确认识仍显不足。

研究组提出了一种通过光致差分电子密度实现分子结构演化原位可视化的实验方案。将该技术应用于芘晶体，揭示了一条未曾预料的激基缔合物形成路径。通过观测光诱导的分子位移与旋转，研究组发现了芘激基缔合物呈现非常规的T形构型——该构型由更紧密相邻的非平行分子构成，这些分子趋向于垂直取向，而非传统认知中由相邻平行分子形成的三明治型构型。此项研究有助于阐明数十年前发现的激基缔合物所涉及的分子取向与构型问题，并为揭示其在生物分子检测、光伏及有机电子学等领域中的基本机制提供了新的视角。

附：英文原文

Title: Unconventional configuration of excimer in luminescent aggregates uncovered by in situ photo-difference electron density

Author: anonymous

Issue&Volume: 2025-12-17

Abstract: Excimers host an important role in nature and modern industrial applications; however, a precise understanding regarding their configuration remains elusive owing to the difficulty in observing their formation in situ. Here we present an experimental scheme enabling in-situ visualization of structural evolution of molecules through photo-difference electron density. Application to pyrene crystals revealed an unanticipated excimer formation pathway. By observing the photo-induced molecular shift and rotation, we discovered the unconventional T-shaped configuration of pyrene excimers, which consists of more closely adjacent nonparallel molecules tending towards a perpendicular orientation, rather than the conventional sandwich configuration formed by adjacent parallel molecules. The results help demystify the molecular orientation and configuration associated with excimer discovered decades ago, and shed light on revealing fundamental mechanism of excimers in the fields of biomolecule detection, photovoltaics, and organic electronics.

DOI: 10.1016/j.cjsc.2025.100846

Source: https://cjsc.ac.cn/cms/issues/945