Crystal Structure of a 4,7-Bis(phenylethynyl)-2,1,3-benzothiadiazole-Based Cyclophane and the Mechanoresponsive Luminescence
作者:Keiko Hiratsuka、Fazil Thuluvanchery Salim、Kiyonori Takahashi、Takayoshi Nakamura、Yoshimitsu Sagara
DOI:10.1246/bcsj.20220216
日期:2022.10.15
grinding to the crystals results in a phase transition to an amorphous state, which is concomitant with an emission color change from green to yellow. Annealing the amorphous phase at 100 °C induces a phase transition to another crystalline state, and green emission was observed again. On subsequent heating, the benzothiadiazole-based cyclophane formed a nematic liquid-crystalline phase above 191 °C.
发光环烷的光物理性质传统上在溶液中以孤立状态进行检查。相比之下,发光环烷响应固态外部刺激的行为还没有完全理解。在此,我们报告了具有一个 4,7-双(苯乙炔基)-2,1,3-苯并噻二唑基团的环烷的晶体结构及其机械变色发光。对晶体进行机械研磨会导致相变到无定形状态,这伴随着发射颜色从绿色变为黄色。在 100 °C 下对非晶相进行退火会导致相变到另一种晶态,并再次观察到绿色发射。在随后的加热中,基于苯并噻二唑的环芳在 191 °C 以上形成向列液晶相。这些结果表明,在环状分子结构中引入 π 扩展的平面发光体是设计刺激响应发光材料的一种很有前景的方法。