Tamboli Majid I, Karothu Durga Prasad, Shashidhar Mysore S, Gonnade Rajesh G, Naumov Panče
CSIR-National Chemical Laboratory, Pune, 411008, India.
New York University Abu Dhabi, P.O. Box 129188, Abu Dhabi, United Arab Emirates.
Chemistry. 2018 Mar 15;24(16):4133-4139. doi: 10.1002/chem.201705586. Epub 2018 Feb 19.
The pincer-like double ester naphthalene-2,3-diyl-bis(4-fluorobenzoate) (2) is pentamorphic. Upon heating crystals of form I to below their melting point (441-443 K), they undergo a phase transition accompanied by a thermosalient effect, that is, rare and visually striking motility whereby the crystals jump or disintegrate. The phase transition and the thermosalient effect are reversible. Analysis of the crystal structure revealed that form I is a class II thermosalient solid. Crystals of form III also underwent a reversible phase transition in the temperature range of 160 to 170 K; however, they were not thermosalient. Comparison of the structures and the mechanical responses of the two polymorphs revealed that the thermosalient effect of form I was due to reversible closing and opening of the arms of the diester molecules in a tweezer-like action.
钳状双酯萘-2,3-二基-双(4-氟苯甲酸酯)(2)具有五种晶型。将晶型I的晶体加热至其熔点(441 - 443 K)以下时，它们会发生相变并伴有热刺激效应，即罕见且视觉上引人注目的运动，晶体在此过程中会跳跃或解体。相变和热刺激效应是可逆的。晶体结构分析表明晶型I是II类热刺激固体。晶型III的晶体在160至170 K的温度范围内也经历了可逆相变；然而，它们没有热刺激现象。两种多晶型物的结构和力学响应的比较表明，晶型I的热刺激效应是由于二酯分子的臂以镊子状作用可逆地闭合和打开所致。
