Wang et al. synthesized phenylacetylene modified HBT derivative (HBT-s-Ph) and diphenylacetylene modified HBT derivative (HBT-d-Ph) with aggregation-induced emission (AIE) phenomenon. In this work, we have theoretically compared the photochemical and photophysical processes of HBT-s-Ph and HBT-d-Ph in the gas phase, toluene and solid phase using several theoretical methods. The ground-state, excited-state equilibrium structures, the potential energy curves and the excited-state properties were comparatively calculated for a better understanding of the AIE mechanism. The excited-state intramolecular proton transfer (ESIPT) process within HBT derivatives is very fast in both gas phase, toluene, and solid phase due to the small energy barrier, inducing the formation of Keto tautomer which is responsible for emission peaks observed in experiment in both gas phase, toluene and solid phase. But, the reaction paths are very different from there. In toluene, the non-radiative path via HBT intramolecular rotation along the C–C bond is favorable to occur, leading to low Φ_f of HBT-s-Ph and HBT-d-Ph in toluene. In contrast, the non-radiative path of HBT intramolecular rotation is strongly suppressed in solid phase due to the high energy barriers, which is responsible for high Φ_f of HBT-s-Ph and HBT-d-Ph in solid phase. The substitution effect on AIE and the large difference of Φ_f in HBT-s-Ph and HBT-d-Ph in solid phase have been revealed. The presents results contribute to a better understanding of the different photophysical properties of HBT derivatives in toluene and solid phase, and unveil the AIE mechanism in HBT derivatives, which provides deep insight into molecular design of organic photoelectric materials with high Φ_f.

王等人。合成了具有聚集诱导发射 (AIE) 现象的苯乙炔改性 HBT 衍生物 (HBT- s -Ph) 和二苯乙炔改性 HBT 衍生物 (HBT- d -Ph)。在这项工作中，我们从理论上比较了 HBT- s -Ph 和 HBT- d的光化学和光物理过程。-Ph 在气相、甲苯和固相中使用了几种理论方法。比较计算了基态、激发态平衡结构、势能曲线和激发态特性，以更好地理解 AIE 机制。由于小的能垒，HBT 衍生物中的激发态分子内质子转移 (ESIPT) 过程在气相、甲苯和固相中都非常快，导致形成酮互变异构体，这是在实验中观察到的发射峰的原因气相、甲苯和固相。但是，反应路径与那里有很大不同。在甲苯中，HBT 分子内沿 C-C 键旋转的非辐射路径有利于发生，导致 HBT- s的Φ _f较低-Ph 和 HBT- d -Ph 在甲苯中。相反，由于高能垒，HBT分子内旋转的非辐射路径在固相中受到强烈抑制，这是固相中HBT- s -Ph和HBT - d -Ph的高Φ _f的原因。揭示了对AIE的取代效应以及固相中HBT-s-Ph和HBT-d-Ph中Φf的巨大差异_。本研究结果有助于更好地理解 HBT 衍生物在甲苯和固相中的不同光物理性质，并揭示 HBT 衍生物中的 AIE 机制，从而深入了解高 Φ 有机光电材料的分子设计。_f .