Cyanide Ligand Assembly by Carbon Atom Transfer to an Iron Nitride.

The new iron(IV) nitride complex PhB(iPr2Im)3Fe≡N reacts with 2 equiv of bis(diisopropylamino)cyclopropenylidene (BAC) to provide PhB(iPr2Im)3Fe(CN)(N2)(BAC). This unusual example of a four-electron reaction involves carbon atom transfer from BAC to create a cyanide ligand along with the alkyne iPr2N-C≡C-NiPr2. The iron complex is in equilibrium with an N2-free species. Further reaction with CO leads to formation of a CO analogue, which can be independently prepared using NaCN as the cyanide source, while reaction with B(C6F5)3 provides the cyanoborane derivative.