Light-Induced Proton Transfer Tautomeric Frustrated Lewis Pairs on Carbon Nitride.

Abstract

The static nature of active sites in heterogeneous frustrated Lewis pairs (FLPs) often limits their adaptability and efficiency in dynamic catalytic environments. Challenges such as the inevitable quenching of sites at high loadings and vulnerability to poisoning restrict their practical application. Inspired by the inherent dynamicity of soft materials, we report a paradigm shift from static design to light-regulated dynamic catalysis by constructing Tautomeric Frustrated Lewis Pairs (TFLPs) on carbon nitride frameworks. Through supramolecular self-assembly, we engineered carbon nitride isomers capable of undergoing photoinduced keto-enol and phosphinylidene tautomerization. This process in situ generates transient, yet stabilized, electron-deficient (Lewis acid) and electron-rich (Lewis base) sites with appropriate spatial frustration. This dynamic system was employed in the photocatalytic oxidation of H₂S, where the TFLPs demonstrated superior and stable activity. In situ spectroscopic studies and kinetic analyses corroborate the light-switched formation of TFLPs and elucidate the dynamic regulatory mechanism. This work establishes tautomerism as a powerful tool for creating adaptive active sites, introducing a new subclass of FLPs and paving the way for intelligent, responsive heterogeneous catalysis.