A series of nitrophenyl substituted carbazole derivatives [9-(4-nitrophenyl)-9H-carbazole (1), 3,9-bis(4-nitrophenyl)-9H-carbazole (2), 9-methyl-3,6-bis(4-nitrophenyl)-9H-carbazole (3), 9-ethyl-3,6-bis(4-nitrophenyl)-9H-carbazole (4), 9-butyl-3,6-bis(4-nitrophenyl)-9H-carbazole (5), 9-hexyl-3,6-bis(4-nitrophenyl)-9H-carbazole (6)] bearing D-π-A systems were prepared and their photophysical properties were investigated comparatively and systematically. Compounds 1, 2, 5 and 6 exhibited obvious aggregation-induced emission properties in DMF/water mixtures and aggregate formation endued them bright luminescence. The elongation of the N-substituted alkyl chains leads to an obvious hypochromatic shift of solid-state fluorescence for compounds 3–6. Specifically, compound 6 showed mechanochromic property involving a reversible interconversion between crystalline form and amorphous phase by mechanical grinding and dichloromethane vapor fuming.

一系列硝基苯基取代的咔唑衍生物[9-（4-硝基苯基）-9 H-咔唑（1），3,9-双（4-硝基苯基）-9 H-咔唑（2），9-甲基-3,6 -双（4-硝基苯基）-9 H-咔唑（3），9-乙基-3,6-双（4-硝基苯基）-9 H-咔唑（4），9-丁基-3,6-双（4） -硝基苯基）-9 H-咔唑（5），9-己基-3,6-双（4-硝基苯基）-9 H-咔唑（6）]带有D-π-A的体系进行了研究，并对其光物理性质进行了研究。比较系统地 化合物1，2，图5和图6在DMF /水混合物中表现出明显的聚集诱导的发射特性，聚集体的形成使它们具有明亮的发光。N取代的烷基链的延长导致化合物3 – 6的固态荧光发生明显的色移。具体地，化合物6显示出机械致变色性质，其涉及通过机械研磨和二氯甲烷蒸气发烟在结晶形式和无定形相之间可逆的相互转化。