Proton and Electron Additions to Iron(II) Dinitrogen Complexes Containing Pendant Amines

Protonation of an iron C–H activated complex containing pendant amines in the presence of N2 generated a cis-(H)­FeII–N2 complex. Addition of acid protonates the pendant amines. Reduction of the protonated complex results in N2 loss and H2 formation, followed by N2 binding. The origin of H2 formation in this Fe system is compared to proposed mechanisms for H2 loss and N2 coordination in the E4 state of nitrogenase.