Arylboron Tetraphenylethylene-Analog AIEgens Enabling Reversible Closed-Shell/Open-Shell Switching

Achieving the synergistic integration of emission regulation and reversible electronic-state switching in aggregation-induced emission (AIE) systems remains challenging, as it requires balancing restriction of intramolecular motion (RIM) with spin delocalization. Here, we construct a class of arylboron-functionalized tetraphenylethylene-analog molecules and systematically elucidate an RIM-governed AIE mechanism via a rotor-locking strategy. Structure-property correlations reveal that rotor positioning decisively dictates conformational freedom and emission behavior, endowing the system with pronounced AIE activity and reversible mechano-/piezochromic responses. Upon electrochemical reduction, stable boron-olefin radicals are generated, exhibiting broadband absorption spanning the visible to the NIR-II region. Leveraging the reversible redox activity of the boron center, electrochemical switching between closed- and open-shell states is achieved, enabling electrochromic devices with high optical contrast and fast response. These systems are further extended to applications in smart displays, large-area smart windows, and light-adaptive electrochromic canopy system.