Wang Jin, Deng Zihao, Ou Xinwen, Chen Xinmeng, Yang Shengyi, Zhang Jianyu, He Xuan, Sun Jianwei, Kwok Ryan T K, Lam Jacky W Y, Tang Ben Zhong
Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Department of Chemical and Biological Engineering, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong 999077, China.
School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Shenzhen 518172, China.
Natl Sci Rev. 2025 Apr 1;12(6):nwaf113. doi: 10.1093/nsr/nwaf113. eCollection 2025 Jun.
Ionic aggregates are among the most common forms of matter, yet the investigation of their molecular motion is often constrained by the instability of isolated anions and cations, as well as the lack of real-time monitoring techniques. This study presents a zwitterionic strategy that integrates both cations and anions into one fluorescent organic framework, forming a zwitterionic molecule. The zwitterionic strategy simplifies the intricate cation-anion systems that are typically found in conventional inorganic salts and imparts them with fluorescent properties, facilitating real-time tracking of ionic-interaction-induced molecular motion within ionic aggregates. Specifically, a blue shift in the fluorescence wavelength signified changes in aggregate states due to intermolecular motion, whereas a decrease in intensity was linked to intramolecular-motion-caused conformational changes. This spontaneous molecular motion enabled dynamic switching of the excited state energy-decay pathway, leading to switchable color-light responses. Overall, the zwitterionic strategy offers a novel framework for exploring the properties and behaviors of molecules in ionic aggregates.
离子聚集体是最常见的物质形式之一，然而对其分子运动的研究常常受到孤立阴离子和阳离子不稳定性以及缺乏实时监测技术的限制。本研究提出了一种两性离子策略，即将阳离子和阴离子整合到一个荧光有机框架中，形成一个两性离子分子。该两性离子策略简化了传统无机盐中常见的复杂阳离子 - 阴离子体系，并赋予它们荧光特性，便于实时跟踪离子聚集体内离子相互作用引起的分子运动。具体而言，荧光波长的蓝移表示由于分子间运动导致的聚集体状态变化，而强度降低与分子内运动引起的构象变化有关。这种自发的分子运动使得激发态能量衰减途径能够动态切换，从而导致可切换的色光响应。总体而言，两性离子策略为探索离子聚集体中分子的性质和行为提供了一个新的框架。
