Photo-triggered phase transition of a crystal
Photo-triggered phase transition of a crystal
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DOI：
10.1038/s42004-019-0121-8
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发表时间：
2019-02-20
影响因子：
5.9
通讯作者：
Koshima, Hideko
中科院分区：
文献类型：
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作者：
Taniguchi, Takuya;Sato, Hiroyasu;Koshima, Hideko
由温度、压力、电磁场和光等外部刺激引起的结构相变在控制固态材料的功能中发挥着至关重要的作用。在这里，我们报告了光致变色手性水杨胺晶体的新相变，称为光触发相变。该晶体表现出在加热和冷却时可逆的热单晶到单晶相变，在低于热转变温度的温度下进行光照射时，该晶体转变为相同的相。光触发相变源于烯醇-酮光异构化产生的反式酮分子的应变，这是由于与晶体结构变化相关的小能垒所致。光触发相是亚稳态的，并通过从反式酮到烯醇形式的反向异构化返回到初始稳定相。
Structural phase transitions induced by external stimuli such as temperature, pressure, electromagnetic fields, and light play crucial roles in controlling the functions of solid-state materials. Here we report a new phase transition, referred to as the photo-triggered phase transition, of a photochromic chiral salicylideneamine crystal. The crystal, which exhibits a thermal single-crystal-to-single-crystal phase transition which is reversible upon heating and cooling, transforms to the identical phase upon light irradiation at temperatures lower than the thermal transition temperature. The photo-triggered phase transition originates from the strain of trans-keto molecules produced by enol-keto photoisomerization owing to the small energy barrier associated with changes in the crystal structure. The photo-triggered phase is metastable and returns to the initial stable phase via back isomerization from the trans-keto to enol form.