Vibrational spectroscopy, electrochemistry, and catalytic competence data for select [(P3E)M(N2)]− complexes. Data for M = Fe, E = B is from refs. 7 and 10; data for M = Fe, E = C is from ref. 8; data for M = Fe, E = Si is taken refs. 8 and 15; and data for M = Co, E = B is from this work. aIR from solid state samples bOxidation potentials determined by cyclic voltammetry in THF. Note: NH3 yields based on the addition of ~ 50 equiv [H•(OEt2)2][BArF4] and ~ 60 equiv KC8 in Et2O (see refs. provided for specific details).