Structure and chemistry of a metal cluster with a four-coordinate carbide carbon atom.

Molecular metal clusters with carbide carbon atoms of low coordination number have been prepared; they are the anionic [HFe(4)C(CO)(12) (-)] and [Fe(4)C(CO)(12) (2-)] clusters. An x-ray crystallographic analysis of a tetraaminozinc salt of the latter has established a butterfly array of iron atoms with the carbide carbon atom centered above the wings of the Fe(4) core. Each iron atom was bonded to three peripheral carbonyl ligands.