Gupta Poonam, Karothu Durga Prasad, Ahmed Ejaz, Naumov Panče, Nath Naba K
Department of Chemistry, National Institute of Technology Meghalaya, India.
New York University Abu Dhabi, Abu Dhabi, United Arab Emirates.
Angew Chem Int Ed Engl. 2018 Jul 9;57(28):8498-8502. doi: 10.1002/anie.201802785. Epub 2018 Jun 10.
The first example of a smart crystalline material, the 2:1 cocrystal of probenecid and 4,4'-azopyridine, which responds reversibly to multiple external stimuli (heat, UV light, and mechanical pressure) by twisting, bending, and elastic deformation without fracture is reported. This material is also able to self-heal on heating and cooling, thereby overcoming the main setbacks of molecular crystals for future applications as crystal actuators. The photo- and thermomechanical effects and self-healing capabilities of the material are rooted in reversible trans-cis isomerization of the azopyridine unit and crystal-to-crystal phase transition. Fairly isotropic intermolecular interactions and interlocked crisscrossed molecular packing secure high elasticity of the crystals.
报道了首个智能晶体材料实例,即丙磺舒与4,4'-偶氮吡啶的2:1共晶体,它通过扭转、弯曲和弹性变形对多种外部刺激(热、紫外光和机械压力)做出可逆响应且不发生断裂。该材料在加热和冷却时还能自我修复,从而克服了分子晶体作为晶体致动器未来应用的主要障碍。材料的光热机械效应和自我修复能力源于偶氮吡啶单元的可逆反式-顺式异构化以及晶型到晶型的相变。相当各向同性的分子间相互作用和互锁的交叉分子堆积确保了晶体的高弹性。