Access to Strong Thieno[3,2-<i>b</i>]phosphole-Based Solid-State Emitters via Manganese(III)-Mediated Oxidative Annulation

Abstract

The synthesis of novel organic molecular frameworks with strong luminescence in the solid state has become an enormously growing area of current research due to their versatile applications for optoelectronics or bioimaging. Here, a facile synthetic strategy via Mn III -mediated oxidative annulation reaction to obtain propeller-rich molecules bearing a thieno[3,2- b ]phosphole motif as a stator moiety is reported. All synthesized compounds show aggregation-induced emission (AIE) characteristics, strong fluorescence in the solid state, and substituent-dependency of the photophysical properties. The phosphinated thieno[3,2- b ]phospholes possess a high degree of restrictions on intramolecular motions, leading to powerful solid-state light emitters with fluorescence quantum yields close to 100% and lifetimes up to 7.9 ns, even at room temperature.