Two twisted π-conjugated cruciform luminophores DMTCS-CC6 and DBTCS-CC6 characterized by rigid X-shaped geometry with two conjugated donor and acceptor intersecting at the central aromatic core have been rationally designed and successfully synthesized. Spectral analysis and theoretical calculations studies indicated that the two cross-conjugated compounds showed unique intramolecular charge-transfer (ICT) process from the donor (carbazole) to the acceptor (dicyanodistyrylbenzene) axis in the excited state. Especially, DMTCS-CC6 and DBTCS-CC6 exhibited efficient aggregation-induced emission (AIE) and high contrast mechanofluorochromic (MFC) properties. By simple grinding, the as-prepared powders of DMTCS-CC6 and DBTCS-CC6 emitting strong yellowish-green (540 nm) and yellow light (560 nm) under UV irradiation could be transferred into powders emitting yellow (582 nm) and red (609 nm), respectively, the red shifts of 42 and 49 nm were observed. Such mechanochromism was reversible upon the treatment of grinding and fuming with DCM. The XRD patterns suggested that the MFC behavior originated from the transition between the crystalline and amorphous states. More interestingly, DBTCS-CC6 exhibited more obvious AIE and more contrast MFC behavior relative to DMTCS-CC6. This is a result of the quite larger space hindrance induced by 3,5-bis(trifluoromethyl)phenyl with two trifluoromethyl groups bonded at meta positions could make DMTCS-CC6 exhibit more twisted spatial conformation, leading more efficient solid state fluorescence and better structural transformability.

合理设计并成功合成了两个扭曲的π共轭十字形发光体DMTCS -CC6和DBTCS-CC6，它们具有刚性的X形几何结构，两个共轭的供体和受体在中心芳族原子处相交。光谱分析和理论计算研究表明，两种交联化合物在激发态下均表现出独特的分子内电荷转移（ICT）过程，从供体（咔唑）到受体（二氰基二苯乙烯基苯）轴。特别地，DMTCS -CC6和DBTCS-CC6表现出有效的聚集诱导发射（AIE）和高对比度的机械荧光致变色（MFC）特性。通过简单研磨，即可制得DMTCS-CC6粉末可以将在紫外线照射下发出强黄绿色（540 nm）和黄光（560 nm）的DBTCS-CC6和DBTCS-CC6分别转移为发出黄色（582 nm）和红色（609 nm）的粉末，其红移为42和49。观察到nm。这种机械变色现象在用DCM处理研磨和发烟后是可逆的。X射线衍射图表明MFC的行为起源于结晶态和非晶态之间的过渡。更有趣的是，DBTCS-CC6显示出较为明显的AIE和对比度MFC相对于更多的行为DMTCS-CC6。这是由于3,5-双（三氟甲基）苯基在间位键合了两个三氟甲基所引起的较大的空间位阻可能导致DMTCS-CC6 表现出更多扭曲的空间构象，导致更有效的固态荧光和更好的结构转化性。