Reduction of dinitrogen bound at an iron(0) centre

It has been confirmed that the deprotonation–reprotonation of dinitrogeniron(II) complexes is a method of producing limited amounts of ammonia. However, the original postulate that such reactions involve an iron(0) dinitrogen complex as the key intermediate may be in error. The species originally identified as such is much more likely to have been a hydrido-complex impurity, and the ammonia-yielding intermediate remains uncharacterised.