文献类型：期刊文献

英文题名：Moisture-Gated Synergistic Rapid Crystal-to-Liquid Transition in Pyridinium Halide Crystals via [2+2] Photocycloaddition

作者：Zhang, Chen-Chen;Chen, Lin;Hou, Jia-Wang;Liu, Jiang-Tao;Lin, Hui-Yao;Xu, Tian-Yi;Tong, Fei[1];Qu, Da-Hui[1]

机构：[1]East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Inst Fine Chem,Sch Chem & Mol Engn,Key Lab Adv Mat, Shanghai, Peoples R China; East China Univ Sci & Technol, Feringa Nobel Prize Scientist Joint Res Ctr, Frontiers Sci Ctr Materiobiol & Dynam Chem, Inst Fine Chem,Sch Chem & Mol Engn,Joint Int Res L, Shanghai, Peoples R China

年份：2026

外文期刊名：SMALL

收录：;EI(收录号：20262520927566);WOS:【SCI-EXPANDED(收录号:WOS:001794147500001)】；

基金：This work was supported by the National Natural Science Foundation of China (22375063, 22405089, 22588101, 22220102004), Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China (JYB2025XDXM404), Science and Technology Commission of Shanghai Municipality (24DX1400200, 23JC1401700), the Innovation Program of Shanghai Municipal Education Commission (2023ZKZD40), the Programme of Introducing Talents of Discipline to Universities (B16017), the Fundamental Research Funds for the Central Universities, and the Guangxi Science and Technology Innovation Platform Program ("Leitai" Action Plan-Guangxi Laboratory Capacity Building) (LT2504240013). We also thank the Research Center of Analysis and Test of East China University of Science and Technology for the help on the characterization.

语种：英文

外文关键词：[2+2] photocycloaddition; dynamic crystals; moisture sensing; phase transition; photoresponse regulation

摘要：Stimuli-responsive dynamic crystals, particularly those that respond to light, offer tremendous potential for developing intelligent materials. Whereas specialized photoresponsive behaviors can be achieved through subtle optical modulation, understanding how these crystals interact with other ambient factors remains equally critical but not fully elucidated. Herein, we show crystals based on methylated pyridinium halide derivatives (MX, X & boxH;Cl, Br, I) that undergo moisture-gated photoinduced crystal-to-liquid transition (PCLT) via [2+2] photocycloaddition at the vinyl structure. Under visible-light irradiation and high local humidity, MX crystals melt rapidly within 1 min (20-50 s). In contrast, under drier conditions, the crystals display vigorous photomechanical motions, including jumping, expanding, and splintering instead. Ambient water molecules surrounding crystal surfaces are found to significantly promote photocycloaddition and stabilize the generated photodimers, leading to a crystal that fully melts outward to inward when local humidity exceeds 60% under light. This process also enables the instant recrystallization growth of photodimer single crystals via a solvent-free approach. Furthermore, we develop a facile sensor system for real-time monitoring of local humidity and for quantifying trace moisture in water-miscible solvents, such as tetrahydrofuran (THF). Our work highlights the significance of synergistic environmental conditions and light stimuli in unlocking advanced functionalities in crystalline materials.