Two tetraphenylethene functionalized β-diketonate boron complexes C2TPE-CAR and C16TPE-CAR that were bridged by carbazole bearing alkyl chains of different lengths, have been designed and successfully synthesized. The two donor–acceptor luminogens showed typical twisted intramolecular charge-transfer (TICT) emission. In particular, they exhibited alkyl-dependent aggregation-induced emission (AIE), self-assembly and mechanofluorochromic (MFC) properties. Results showed that C16TPE-CAR with a long hexadecyl chain formed gels in certain solvents and also exhibited gelation-induced emission enhancement. H-aggregates were formed driven by the synergistic effect of π-stacking interaction and van der Waals force in the gel phase. However, C2TPE-CAR, which possessed the short ethyl group, exhibited no self-assembly behavior. Simple mechanical force could change the emission color of C2TPE-CAR and C16TPE-CAR powders from initial bright yellow (571 and 558 nm) to final red (617 and 610 nm), thus high contrast mechanofluorochromism with large spectral shifts of up to 46 and 52 nm, respectively, was observed. The powder XRD studies showed that the MFC behavior might be switched reversibly under the stimulus of external force because of crystalline-amorphous phase transformation.

已设计并成功合成了两种四苯基乙烯官能化的β-二酮硼酸酯硼配合物C2TPE-CAR和C16TPE-CAR，它们由带有不同长度烷基链的咔唑桥接。两种供体-受体发光剂显示出典型的扭曲的分子内电荷转移（TICT）发射。特别是，它们表现出烷基依赖性的聚集诱导发射（AIE），自组装和机械荧光致变色（MFC）特性。结果表明，具有十六烷基长链的C16TPE-CAR在某些溶剂中形成凝胶，并且还表现出胶凝诱导的发射增强。在凝胶相中，π堆积相互作用和范德华力的协同作用驱动形成H聚集体。但是，C2TPE-CAR具有短的乙基的化合物，没有表现出自组装行为。简单的机械力就能将C2TPE-CAR和C16TPE-CAR粉末的发射颜色从最初的亮黄色（571和558 nm）改变为最终的红色（617和610 nm），因此具有高对比度的机械荧光致变色，光谱移动最大可达46和观察到分别为52nm。粉末XRD研究表明，由于结晶-非晶相变，在外力的刺激下，MFC的行为可能可逆地转换。