Photo‐Enhanced‐Coordination Triggered Unprecedented Bistable AIE for Long‐Term Optical Memories

Abstract

AbstractPhoto‐triggered chromism has emerged as critically important in materials for advanced soft photonic devices. The conventional photochromic units with reversible color change between two isomers are unstable either thermally or photochemically, which is an important challenge for long‐standing optical devices. Here, a novel photo‐enhanced coordination mechanism leading to stable chromism is reported. Upon tethering the aggregation‐induced emission (AIE) moiety diphenyldibenzofulvene (PBF) to a dicarboxylic pyridine group, photo‐irradiation triggers the coordination transition between the carbonate groups and Mg2+ from bidentate to the more stable bridging mode, which further influences the conformation of the remote PBF group, leading to transition of the emission color from cyan to yellow. Under ambient conditions, both coordinating isomers display excellent thermal and photochemical stability. As a result, the photo writings on the films based on the coordinating AIE materials exhibit the long‐term stability, which barely fades even upon heating, vapor fuming, or day‐light exposure. This photo‐enhanced‐coordination enabled bistable chromism is expected to open a new vista in the study of chromism and high durable optical memories.