Tetraphenylethene derivatives with AIE-ESIPT characteristics: Synthesis, crystal structures, photophysical properties and application for ClO− detection and pH sensing

The fluorescent probe with both aggregation-induced emission (AIE) and excited-state intramolecular proton transfer (ESIPT) shows significant advantages, such as no self-quenching at high concentration, large Stokes shift, high selectivity towards analyte etc. Based on tetraphenylethene and ESIPT structural modules, three AIE-ESIPT molecules containing one different atom (S, O, N) have been constructed in this paper. The effects of three atoms on the optical properties of fluorescent molecules have been investigated by fluorescence spectroscopy and X-ray crystallographic analyses. Interestingly, the cyclic detection of HCl and NH3 gases can be achieved with the BTY-TPE-based portable test paper. In addition, BOY-TPE and HBIY-TPE can detect ClO− by naked eye with low detection limit, good biocompatibility.