Two α-cyanostilbene derivatives NCS1 and NCS2 were designed and synthesized. Both two compounds exhibited AIE properties. Solid compounds showed excellent mechanochromism with 29/26 nm redshift and distinct acid-base vapor chromotropism, which could be applied for relevant sensors. XRSD and PXRD spectra revealed the intrinsic relationship between mechanochromism and molecular packing mode. The twisted molecular conformation became more planar with an increase in conjugation after grinding, resulting in the redshift in fluorescence spectra. Moreover, the emission spectra of NCSs showed obvious fluorescence quenching for p-nitroaniline (PNA) with excellent selectivity. The fluorescence intensity showed better linear relationship at low concentration of PNA. The limit of detections were as low as 0.42 μmol L^-1 and 0.60 μmol L^-1, respectively. DFT theory proved that this sensing mechanism was attributed to the process of photoinduced electron transfer (PET). Importantly, NCSs were successfully used for PNA detection in real environments. We provide the working basis for developing high-performance multi-functional materials.

设计并合成了两种α-氰基二苯乙烯衍生物NCS1和NCS2。两种化合物均显示出AIE性质。固体化合物具有出色的机械变色性，具有29/26 nm的红移和明显的酸碱蒸气变色性，可用于相关传感器。XRSD和PXRD光谱揭示了机械变色与分子堆积模式之间的内在联系。研磨后，扭曲的分子构象变得更平坦，共轭增加，导致荧光光谱发生红移。此外，NCS的发射光谱对对硝基苯胺（PNA）表现出明显的荧光猝灭，选择性极好。在低浓度的PNA下，荧光强度表现出较好的线性关系。检出限分别低至0.42μmolL ^-1和0.60μmolL ^-1。DFT理论证明，这种感应机制归因于光致电子转移（PET）的过程。重要的是，NCS已成功用于实际环境中的PNA检测。我们为开发高性能多功能材料提供了工作基础。