A new TICT and AIE-active tetraphenylethene-based Schiff base with reversible piezofluorochromism

A new tetraphenylethene-based Schiff base N-5-nitrosalicylidene-4-tetraphenylethenylamine (NSTPE) was synthesized based on 4-tetraphenylethenylamine and 5-nitrosalicylaldehyde, and its structure was fully characterized by H-1 NMR, C-13 NMR, MS and single crystal X-ray diffraction analysis. The study of optical properties shows that the emission exhibits an interesting on-off-on switching property with a U-shaped tendency when adding water into the tetrahydrofuran solution of NSTPE, showing twisted intramolecular charge transfer (TICT) and aggregation-induced emission (AIE) characteristics. Moreover, the compound exhibits reversible piezofluorochromic properties.