A Thiolate‐Bridged Diiron Parent μ ‐Imide Involving as a Key Junction in the Bidirectional Interconversion Between Nitride and Amide

ABSTRACT Iron parent imides serve as key intermediates for iron‐promoted nitrogen fixation and ammonia oxidation. However, these active species are difficult to be isolated, and their reactivities are underexplored. So far, only a few multinuclear iron parent imides were reported, but none plays a key intersection during the bidirectional transformation. Herein, we adopt the bulky 1,2,4‐tri( tert ‐butyl)cyclopentadienyl (Cp′) and bidentate 1,3‐propanedithiolate (pdt) ligand to provide the steric protection for the reactive [Fe 2 S 2 ] scaffold. As predicted, the highly active imido species can be captured by this [Fe 2 S 2 ] platform to generate a novel thiolate‐bridged diiron parent μ ‐imide complex 3 . Mössbauer spectroscopy and DFT calculation reveal that 3 features a bent {Fe III −NH 2− −Fe III } framework with two anti‐ferromagnetic coupled, low‐spin Fe(III) centers. Importantly, imide 3 can not only undergo protonation to generate amide and finally release ammonia, but also go through hydrogen atom transfer to regenerate nitride. This reactivity indicates that 3 is a key junction that associates the late stage (N 3− → NH 2− → NH 2 − → NH 3 ) of nitrogen fixation and the initial period (NH 2 − → NH 2− → N 3− ) of ammonia oxidation. Overall, this work provides one available strategy that can stabilize a high‐activity imide and investigate its reactivity of bidirectional interconversion.