Most organic mechanochromic luminogens show bathochromic-shifted and quenched emission with increasing pressure. Design of turn-on mechanochromic material with hypsochromic-shifted luminescence is still a challenge. Herein, a novel emitter (namely DCzPy) was prepared through laboratory-synthesized carbazole to study its stimuli-responsive luminescence. The crystalline powders of DCzPy emitted blue-green fluorescence at 490 nm. Upon gently grinding, the fluorescence intensity of DCzPy was dramatically enhanced with a hypsochromic shift by 33 nm. Further heavily grinding, its emission wavelength returned to 490 nm. Powder X-ray diffraction patterns indicated that such behaviors were attributed to the solid-state morphology transition from crystal to crystal. Interestingly, a large bathochromic-shifted and weakened fluorescence was achieved under isotropic compression. Moreover, thermoresponsive behavior of DCzPy was studied in the film to find that its emission turned from green to blue as the temperature increased. Given the thermo-induced fluorescence switching of DCzPy, a two-dimensional code was fabricated for information anticounterfeiting.

中文翻译：

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基于咔唑发射体的压力/热诱导的浅色位移和增强发光

随着压力的增加，大多数有机机械致色发光体显示出红移和猝灭发射。具有向色位移发光的开启机械变色材料的设计仍然是一个挑战。在此，通过实验室合成的咔唑制备了一种新型发光体（即 DCzPy），以研究其刺激响应发光。DCzPy 的结晶粉末在 490 nm 处发出蓝绿色荧光。轻轻研磨后，DCzPy 的荧光强度随着 33 nm 的向色偏移而显着增强。进一步重磨，其发射波长恢复到 490 nm。粉末 X 射线衍射图表明，这种行为归因于从晶体到晶体的固态形态转变。有趣的是，在各向同性压缩下实现了大的红移和减弱的荧光。此外，在薄膜中研究了 DCzPy 的热响应行为，发现其发射随着温度升高从绿色变为蓝色。鉴于 DCzPy 的热诱导荧光开关，制作了二维码用于信息防伪。