文献类型：期刊文献

英文题名：Engineering Photomechanical Molecular Crystals to Achieve Extraordinary Expansion Based on Solid-State [2+2] Photocycloaddition

作者：Xu, Tian-Yi[1,2];Tong, Fei[1,2];Xu, Hui[1,2];Wang, Meng-Qi[1,2];Tian, He[1,2];Qu, Da-Hui[1,2]

机构：[1]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem,Feringa Nobel Prize Scientist Join, Frontiers Sci Ctr Materiobiol & Dynam Chem,Key La, Shanghai 200237, Peoples R China;[2]East China Univ Sci & Technol, Sch Chem & Mol Engn, Inst Fine Chem,Feringa Nobel Prize Scientist Join, Frontiers Sci Ctr Materiobiol & Dynam Chem,Joint, Shanghai 200237, Peoples R China

年份：2022

卷号：144

期号：14

起止页码：6278

外文期刊名：JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

收录：;EI(收录号：20221311866494);WOS:【SCI-EXPANDED(收录号:WOS:000790698300020)】；

基金：This work was financially supported by the National Natural Science Foundation of China (NSFC) (grants 22025503, 22105071, 21790361, and 21871084), the Shanghai Municipal Science and Technology Major Project (grant 2018SHZDZX03), the Fundamental Research Funds for the Central Universities, the Programme of Introducing Talents of Discipline to Universities (grant B16017), Shanghai Sailing Program (21YF1409200), the Program of Shanghai Academic/Technology Research Leader (19XD1421100), the Science andJournal of the American Chemical Society pubs.acs.org/JACS Article Technology Commission of Shanghai Municipality (21JC1401700), and the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study (SN-ZJUSIAS-006). The authors also thank the Research Center of Analysis and Test of East China University of Science and Technology for help on the material characterization.

语种：英文

外文关键词：Anisotropy - Elongation - Light - Geometry - Microcrystals - Crystal structure - Molecular crystals

摘要：Photomechanical molecular crystals are promising candidates for photoactuators and can potentially be implemented as smart materials in various fields. Here, we synthesized a new molecular crystal, (E)-3-(naphthalen-1-yl)acrylaldehyde malononitrile ((E)-NAAM), that can undergo a solid-state [2 + 2] photocycloaddition reaction under visible light (>= 400 nm) illumination. (E)-NAAM microcrystals containing symmetric twinned sealed cavities were prepared using a surfactant-mediated crystal seeded growth method. When exposed to light, the hollow microcrystals exhibited robust photomechanical motions, including bending and dramatic directional expansion of up to 43.1% elongation of the original crystal length before fragmentation due to the photosalient effect. The sealed cavities inside the microcrystals could store different aqueous dye solutions for approximately one month and release the solutions instantly upon light irradiation. A unique slow-fast-slow crystal elongation kinematic process was observed, suggesting significant molecular rearrangements during the illumination period, leading to an average anisotropic crystal elongation of 37.0% (+/- 3.8%). The significant molecular structure and geometry changes accompanying the photocycloaddition reaction, which propels photochemistry to nearly 100% completion, also facilitate photomechanical crystal expansion. Our results provide a possible way to rationally design molecular structures and engineer crystal morphologies to promote more interesting photomechanical behaviors.