Yuhara Kazuhiro, Tanaka Kazuo
Department of Polymer Chemistry, Graduate School of Engineering, Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan
Department of Technology and Ecology, Graduate School of Global Environmental Studies, Kyoto University Katsura, Nishikyo-ku Kyoto 615-8510 Japan.
Chem Sci. 2025 Mar 17;16(15):6495-6506. doi: 10.1039/d5sc00875a. eCollection 2025 Apr 9.
Here, we show mechanistic analyses of solid-state temperature-dependent luminescence of ,'-diaryl--carborane derivatives. Solid-state stimuli-responsiveness is a promising property to visualize environmental changes on the molecular scale. Thus, mechanistic study of responsiveness is meaningful for broadening the scope of materials. We previously reported solid-state temperature-dependent luminochromism of -anthryl--carborane derivatives. Among them, we re-focused on -anthryl-'-phenyl--carborane as a prototypical compound and synthesized derivatives with electronically different substituents on aryl units. Based on extensive analyses with crystallography, variable temperature optical measurements and theoretical calculation, we show that luminochromic behaviors can be explained by partially restricted excited-state elongation of the carbon-carbon bond in the cluster. Our results indicate that thermal expansion and contraction of the crystalline lattice should play a key role in modulating the degree of excited-state structural relaxation including the bond elongation in the cluster.
在此，我们展示了对α,α'-二芳基-α-碳硼烷衍生物固态温度依赖性发光的机理分析。固态刺激响应性是一种在分子尺度上可视化环境变化的有前景的特性。因此，对响应性的机理研究对于拓宽材料范围具有重要意义。我们之前报道了α-蒽基-α-碳硼烷衍生物的固态温度依赖性发光变色现象。其中，我们重新聚焦于α-蒽基-α'-苯基-α-碳硼烷作为典型化合物，并合成了在芳基单元上具有电子性质不同取代基的衍生物。基于晶体学、变温光学测量和理论计算的广泛分析，我们表明发光变色行为可以通过簇中碳 - 碳键的部分受限激发态伸长来解释。我们的结果表明，晶格的热膨胀和收缩在调节包括簇中键伸长在内的激发态结构弛豫程度方面应起关键作用。
