AIE Ligand Constructed Zn(II) Complex with Reversible Photo-induced Color and Emission Changes

Fluoran salicylaldehyde hydrazone metal complex(FSHMC) is a kind of recently reported photo-responsive system, which has the advantages of simple synthesis, multiple colors as well as distinct color change before and after UV light irradiation. However, the emission property of FSHMC is relatively unitary. In solid state, especially, only fluorescence quench is induced after UV light irradiation, which limits their applications. In this work, a typical aggregation-induced emission(AIE) moiety of tetraphenylethene(TPE) was introduced to the design of FSHMC. The obtained FSHMC, 2-Zn, exhibited reversible color and fluorescence changes upon UV light irradiation. Due to the AIE feature of compound 2, 2-Zn exhibited different emission changes upon UV light irradiation in THF and in solid matrix, because of the fluorescence resonance energy transfer(FRET) process from TPE moiety to rhodamine B moiety.