Spin-State Manipulation in a Luminescent Diradical Polymer

Controlling the spin states to modulate their optical properties is crucial for spintronics and emerging quantum technologies. Open-shell luminescent diradicals are promising candidates for achieving this goal due to the independent spins. However, achieving spin-optical modulation in traditional diradicals still faces significant challenges owing to low luminescence efficiency and inevitable aggregate effects. In this study, we first achieved efficient luminescence of a diradical by suspending luminescent diradicals on a polymer main chain. The resulting diradical polymer exhibits a high photoluminescence efficiency of 44.0% in the condensed state along with excellent photostability. Most importantly, we have demonstrated successful spin-state manipulation through temperature control and application of a magnetic field. These findings open up new avenues for spin-optical modulation based on luminescent diradical materials, providing important guidance for the development spin-optoelectronics.