Multiring-induced multicolour emission: hyperbranched polysiloxane with silicon bridge for data encryption

Abstract

Multicolour emissive nonconventional macromolecular luminogens with aggregation-induced emission have drawn great attention due to their potential application in a wide range of areas. However, the exploration of efficient synthetic strategies and emission mechanisms still remains a challenge. Herein, we report a facile route to the synthesis of hyperbranched polysiloxane (P1) with adjacent –CO and –CC groups. Surprisingly, it not only showed blue emission under white light excitation, but also exhibited multicolour luminescence under different excitation wavelengths. Especially, multiple through-space conjugation rings can be found between the first generation P1 molecules via DFT calculation; based on its remarkable luminescence properties, we proposed a new luminescence mechanism namely “multiring-induced multicolour emission” (MIE). In addition, the stimuli-responsive behaviour of P1 as well as its application in data encryption based on the quenching effect of Fe³⁺ was studied. This work provides guidance to design and synthesise nonconventional macromolecular AIEgens with multicolour luminescence.