Thanks to the coplanar configuration, high electron communication or charge carrier mobility, Cz is widely used to construct stimuli-responsive smart materials , thermally activated delayed fluorescence emitters , organic luminescent radicals and room temperature organic phosphorescence materials , and many of them have directly made significant breakthroughs in the related fields. For example, numerous room-temperature phosphorescence (RTP) materials were constructed by using Cz unit depending on their Haggregation . As well know, Cz was successfully refined from coal tar one hundred years ago, which is the main source of commercial Cz. However, Liu recently found that trace isomer (1H-benzo[f]indole, Bi) existed in commercial Cz played a vital role in ultralong phosphorescence emission . Then, Ma synthesized the Cz and isomer Bi derivatives to further elucidate the mechanism of Cz-based RTP . Taking these into account, the isomer Bi has a huge impact on the phosphorescence behaviors of Cz derivatives. To exclude the effect of the isomer Bi on the stimuli-responsive luminescence, here we used the lab-synthesized Cz as starting material to construct a donor (D)-acceptor (A) structure. The lab-synthesized Cz was obtained as a white powder from N-(2-bromophenyl) aniline according to previous literature . DCzPy was synthesized by one-step SNAr reaction of Cz and 2, 6-dichloropyridine-3, 5-dicarbonitrile. 1 H NMR, 13 C NMR, high-resolution mass spectrometry (HRMS) and crystallographic analyses were carried out to confirm their molecular structures. The detailed synthetic procedures and molecular characterizations are presented in the Supporting Information (Figs. ).