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

A tin-supported iron catalyst produces 5.9 turnovers of NH(3)from N-2, using [Ph2NH2]OTf as the acid and CoCp2* as the reductant. Two redox states of the Fe(N-2) adduct and an Fe silyldiazenido complex were characterized using X-ray crystallography along with NMR and Mossbauer spectroscopies. Density functional theory calculations reveal that the charge on the Sn center correlates strongly with both the polarization of the N(2)moiety and the charge on the distal N atom.