Substituent-modulated aggregation-induced emission and solid-state acid/base sensing applications of pyrazole-based donor-acceptor derivatives

Abstract

AIE-active luminophores (PYZ1−PYZ4) containing substituted pyrazole as a donor and cyanomethylene/benzothiazole as acceptor units have been synthesized and thoroughly characterized by IR, 1H/13C NMR, HRMS and single crystal X-ray diffraction analyses. These new systems exhibited efficient aggregation induced emission and solid-state emission with good quantum yield. Interestingly, these compounds display acid/base-induced reversible solid-state fluorescence switching, and could be used as a solid-state acid/base sensor. Structure-property relationship investigations clearly showed that structural changes strongly influence photophysical properties of these compounds. © 2022