A tetraphenylethylene-based acylhydrazone Schiff base macrocycle exhibiting aggregation-induced emission and "turn-on" detection of Al3+ ions.

A tetraphenylethylene-based acylhydrazone macrocycle (H 8 L) was designed and synthesized via Schiff base condensation reaction. The [2 + 2] molecular structure of H 8 L was determined via 1H NMR, 13C NMR, elemental analysis, ESI-MS, and single crystal X-ray diffraction. The "ESIPT + AIE" and selective recognition properties of macrocycle H 8 L were investigated via UV–vis absorption spectra and fluorescence emission spectra. The results showed that macrocycle H 8 L exhibited an obvious AIE characteristic in THF/H 2 O solution with varying water fraction, and displayed a selective "turn-on" response to Al3+ ions in the solution of THF/H 2 O (V : V = 4: 1). In addition, the visualization of latent fingerprints and the application of H 8 L on test strips were performed as well. A tetraphenylethylene-based Schiff base macrocycle (H 8 L) has been synthesized and characterized. The luminescence spectra disclosed that H 8 L displayed a selective recognition and acted as a "turn-on" fluorescent sensor to Al3+ ions in THF/H 2 O solution. The application of H 8 L on latent fingerprints and test strips indicated that H 8 L can be used as a promising fluorescent material. [Display omitted] • The luminescence spectra showed an ESIPT and AIE characteristic of macrocycle H 8 L in the THF/H 2 O solution with different water fraction. • H 8 L displayed a selective recognition and acted as a "turn-on" fluorescent sensor for Al3+ ions in the THF/H 2 O solution. • The application of H 8 L on latent fingerprints and test strips indicated that it can be used as a promising fluorescent material. [ABSTRACT FROM AUTHOR]