Bioinspired Atomic Manganese Site Accelerates Oxo-Dehydrogenation Of N-Heterocycles Over A Conjugated Tri-S-Triazine Framework

Herein, taking inspirations from metalloenzymes, we constructed atomically dispersed manganese sites anchored onto conjugated tri-s-triazine units of graphitic carbon nitride as a bioinspired photocatalyst (Mn-1/tri-CN) for the oxo-dehydrogenation of N-heterocycles. The primary coordination sphere of atomic Mn-N-2 sites (role i: oxygen activation) as well as the pi-pi stacking interactions between tri-s-triazine units and substrate mimicking the secondary coordination sphere (role ii: substrate adsorption) synergistically realized high-efficiency electron transfer/utilization in photocatalytic oxidation reactions, as was demonstrated experimentally and theoretically. The Mn-1/tri-CN catalyst exhibited impressive oxo-dehydrogenation activity and selectivity toward a broad scope of N-heterocycles in an air atmosphere. The current work suggests that simultaneously engineering the metal active sites of catalysts and the adaptive local environment of the matrix may open an avenue for the synthesis of fine chemicals.