High-contrast mechanochromic benzothiadiazole derivatives based on a triphenylamine or a carbazole unit.

Four triphenylamine or carbazole-based benzothiadiazole fluorescent molecules have been successfully synthesized and characterized. Interestingly, the donor-acceptor (D-A) type luminogens 1, 2, 3 and 4 showed different solid-state fluorescence. Furthermore, the four compounds exhibited reversible high-contrast mechanochromism characteristics.