Redox triggered aggregation induced emission (AIE) polymers with azobenzene pendants

Abstract

We reported the redox triggered aggregation induced emission (AIE) polymers with azobenzene pendants. Tetraphenylethene (TPE) based polymers with selected degrees of functionalization of azobenzene chromophores were synthesized through a post-polymerization azo-coupling scheme. Due to the fluorescence resonance energy transfer (FRET) process, the excited energy of the fluorescent TPE parts could be transferred to the azobenzene chromophores, so that the fluorescent states of TPE parts would be well quenched. The degrees of functionalization of the azobenzene chromophores have shown much effect on this FRET process. By the reduction of azobenzene chromophores upon treatment with hydrazine hydrate, the strong fluorescence of the TPE based polymers would recover again. Besides in solution, this redox reaction triggered fluorescence of azobenzene containing polymers could also be found in their solid films.