Ito Suguru, Wakiyama Shin, Chen Hao, Abekura Masato, Uekusa Hidehiro, Ikemura Ryoya, Imai Yoshitane
Department of Chemistry and Life Science, Graduate School of Engineering Science, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama, 240-8501, Japan.
PRESTO, Japan Science and Technology Agency (JST), 4-1-8 Honcho, Kawaguchi, Saitama, 332-0012, Japan.
Angew Chem Int Ed Engl. 2025 Mar 10;64(11):e202422913. doi: 10.1002/anie.202422913. Epub 2025 Jan 22.
Circularly polarized luminescence (CPL) and mechanochromic luminescence (MCL) have independently made substantial progress in recent years. However, the exploration of MCL in solid-state CPL materials, which holds practical significance, is still in its infancy. Herein, we report the MCL properties of readily accessible chiral pyrenylprolinamides bearing tert-butoxycarbonyl (Boc) or 2,2,2-trichloroethoxycarbonyl (Troc) groups. Enantiopure crystals of the Boc derivative display a greater MCL wavelength shift than racemic crystals, while the Troc derivative exhibit the opposite trend. Most notably, the enantiopure crystals show mechanochromic CPL. Unlike in previous examples, where CPL is quenched upon amorphization, robust CPL spectra were observed even in the amorphous states. By applying the excimer chirality rule, we have, for the first time, acquired insights into the excited-state structures within mechanically generated amorphous states. These findings offer a novel design strategy for developing mechanochromic CPL materials, paving the way for the future advancements in this emerging field.
近年来，圆偏振发光（CPL）和机械变色发光（MCL）各自都取得了重大进展。然而，对具有实际意义的固态CPL材料中的MCL的探索仍处于起步阶段。在此，我们报道了带有叔丁氧羰基（Boc）或三氯乙氧羰基（Troc）基团的易于获得的手性芘基脯氨酰胺的MCL性质。Boc衍生物的对映体纯晶体显示出比外消旋晶体更大的MCL波长位移，而Troc衍生物则呈现相反的趋势。最值得注意的是，对映体纯晶体表现出机械变色CPL。与之前CPL在非晶化时淬灭的例子不同，即使在非晶态下也观察到了稳健的CPL光谱。通过应用准分子手性规则，我们首次深入了解了机械生成的非晶态中的激发态结构。这些发现为开发机械变色CPL材料提供了一种新颖的设计策略，为这一新兴领域的未来发展铺平了道路。
