Ammonia Formation Catalyzed by a Dinitrogen?Bridged Dirhenium Complex Bearing PNP?Pincer Ligands under Mild Reaction Conditions**

A series of rhenium complexes bearing a pyridine-based PNP-type pincer ligand are synthesized from phosphine as precursors. dinitrogen-bridged dirhenium complex the ligands catalytically converts dinitrogen into ammonia during reaction with KC8 reductant and [HPCy3]BArF4 (Cy=cyclohexyl, ArF=3,5-(CF3)2C6H3) proton source at ?78 °C to afford 8.4 equiv based on atom catalyst. The rhenium-dinitrogen also catalyzes silylation in Me3SiCl silylating reagent under ambient conditions 11.7 tris(trimethylsilyl)amine These results demonstrate first successful example catalytic nitrogen fixation mild using catalysts.