近日，华东理工大学曲大辉团队研究了基于自适应氢键网络重构的剪切力剪切有机分子晶体。这一研究成果于2025年9月23日发表在《美国化学会志》上。

有机分子晶体通常被认为是脆弱易碎的，并且容易解体，特别是在各向异性剪切力的作用下。然而，微小的分子间相互作用和微妙的分子填充基序可能使晶格具有非凡的机械性能。

研究组提出了一种由手性二硫烷衍生物（R-TAE）组成的有机分子晶体，它可以通过外部剪切力剪切成任意形状。通过三溶剂扩散法制备的宏观R-TAE晶体可以用镊子机械撕裂，也可以用普通剪刀进行主题化，精确切割成半圆、三角形、三角波、五边形、星形等理想形状，同时保持较高的结晶度和结构完整性。与外消旋晶体（RS-TAE）相比，R-TAE晶体具有更灵活的自适应晶格，使晶体在机械应力下可逆地弯曲和卷曲。非常规但简单的晶体形状编程特性源于特定的分子设计和组织，其固有地结合了R-TAE晶格中的手性对称性破坏效应。

此外，高不对称性有助于在剪切力驱动下自适应氢键网络重构过程中的有效能量耗散和晶体在剪切力作用下的晶格滑移。在紫外线诱导的二硫键重组后，R-TAE晶体没有破裂或破碎，而是保持了其整体形态的完整，并表现出显著的弹性模量增强，这表明R-TAE晶体对光诱导内应力的抵抗能力较强。该研究强调了自上而下和自下而上方法的战略整合，从而产生具有理想各向异性特性的动态晶体，并使其具有精确和直接的可加工性。

附：英文原文

Title: Shear Force Cropping Organic Molecular Crystals Based on Adaptive Hydrogen Bonding Network Reconstructions

Author: Hui-Yao Lin, Le Li, Chengxi Zhao, Fei Tong, Qi Zhang, Chengyuan Yu, He Tian, Ben L. Feringa, Da-Hui Qu

Issue&Volume: September 23, 2025

Abstract: Organic molecular crystals are stereotypically considered brittle, fragile, and prone to disintegration, especially when under anisotropic shear forces. However, robust intermolecular interactions and subtle molecular packing motifs may enable a crystal lattice with extraordinary mechanical properties. Here, we present an organic molecular crystal composed of a chiral dithiolane derivative (R-TAE) that can be cropped and cut into arbitrary shapes by external shear forces. Macroscopic R-TAE crystals prepared through a three-solvent diffusion method can be mechanically torn apart by tweezers or precisely cut into desirable shapes, such as semicircles, triangles, triangular waves, pentagons, and stars, by using ordinary scissors, while retaining high crystallinity and structural integrity. Compared with the racemic crystals (RS-TAE), an R-TAE crystal possesses a more flexible and adaptive lattice, enabling the crystal to bend and curl under mechanical stress reversibly. The unconventional yet simple crystal shape programming peculiarity emanates from a specific molecular design and organization that inherently incorporate chiral symmetry-breaking effects in the R-TAE crystal lattice. Moreover, it is revealed that the high asymmetry facilitates effective energy dissipation during the shear force-driven reconstruction of the adaptable hydrogen-bonding network and crystal lattice slippage when the crystal is subjected to shear forces. Instead of cracking or shattering, R-TAE crystals retain their overall morphology intact and exhibit a significant elastic modulus enhancement after ultraviolet-induced disulfide bond reorganization, suggesting robust resistance to photoinduced internal stress. Our research highlights the strategic integration of top-down and bottom-up approaches, resulting in dynamic crystals with desirable anisotropic properties and enabling their precise and straightforward processability.

DOI: 10.1021/jacs.5c10822

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.5c10822