Bimetallic iron–tin catalyst for N2 to NH3 and a silyldiazenido model intermediate

Abstract

A tin-supported iron catalyst produces 5.9 turnovers of NH₃ from N₂, using [Ph₂NH₂]OTf as the acid and CoCp₂* as the reductant. Two redox states of the Fe(N₂) adduct and an Fe silyldiazenido complex were characterized using X-ray crystallography along with NMR and Mössbauer spectroscopies. Density functional theory calculations reveal that the charge on the Sn center correlates strongly with both the polarization of the N₂ moiety and the charge on the distal N atom.