New York University Abu Dhabi , P. O. Box 129188, Abu Dhabi, United Arab Emirates.
Max Planck Institute for Solid State Research , Heisenbergstrasse 1, D-70569 Stuttgart, Germany.
J Am Chem Soc. 2015 Nov 4;137(43):13866-75. doi: 10.1021/jacs.5b07806. Epub 2015 Oct 20.
The increasing number of reports on photomechanical effects in molecular crystals necessitates systematic studies to understand the intrinsic and external effectors that determine and have predictive power of their type and magnitude. Differential light absorption and product gradient between the surface and the bulk of the crystal are often invoked to qualitatively explain the mechanical response of crystals to light; however, the details on how this difference in photochemical response accounts for macroscopic effects such as surface modification, deformation, or disintegration of crystals are yet to be established. Using both bulk- and surface-sensitive analytical techniques, a rare instance of benzylidenefuranone crystals is studied here, and it is capable of several distinct types of photomechanical response including surface striation and delamination, photosalient effect (ballistic disintegration and motion), and photoinduced bending by dimerization. The results provide a holistic view on these effects and set the stage for the development of overarching theoretical models to describe the photomechanics in the ordered solid state.
越来越多的关于分子晶体的光机械效应的报道需要系统的研究来理解决定其类型和大小的内在和外在效应因子，并具有预测能力。光吸收的差异和晶体表面与内部之间的产物梯度通常被用来定性地解释晶体对光的机械响应；然而，对于这种光化学反应的差异如何解释表面修饰、变形或晶体分解等宏观效应，仍有待确定。本文使用了体相和表面敏感的分析技术，对苯亚甲基呋喃酮晶体这一罕见实例进行了研究，它能够产生几种不同类型的光机械响应，包括表面条纹和分层、光敏效应（弹道式分解和运动）以及通过二聚化产生的光致弯曲。这些结果提供了对这些效应的全面了解，并为开发描述有序固态中光机械的综合理论模型奠定了基础。
