A multi-responsive AIE-active tetraphenylethylene-functioned salicylaldehyde-based schiff base for reversible mechanofluorochromism and Zn2+ and CO32- detection

In this work, a tetraphenylethylene-functioned salicylaldehyde-based AIE-active Schiff-base (TPEMO) has been designed and synthesized. Interestingly, the compound showed reversible mechanofluorochromism (MFC) with its emission color change from yellowish green to orange-yellow after grinding. Furthermore, TPEMO exhibited high selectivity and sensitivity towards Zn2+ over other commonly coexisting metal ions with a low detection limit of 8.05 x 10(-8) M due to the inhibition of the photo induced electron transfer (PET) and the excited-state intramolecular proton transfer (ESIPT). Job's plot and the HR-MS spectrum confirmed the TPEMO and Zn2+ binding in 1:1 bonding model. Moreover, TPEMO could sensitively detect towards CO32- with a 1:1 stoichiometry, and exhibited an obviously fluorescence (from blue to bright orange) changes with 95 nm red-shift in emission spectra during the recognition process. And the detection limit of TPEMO for CO32- was found to be about 7.12 x 10(-8) M.