Two Exceptional Homoleptic Iron(IV) Tetraalkyl Complexes.

The formation of the high-valent iron complex [Fe(cyclohexyl)4 ] from FeII under reducing conditions is best explained by disproportionation of a transient organoiron intermediate which is driven by dispersive forces between the cyclohexyl ligands and the formation of short and strong Fe-C bonds. The (meta)stability of this diamagnetic complex (S=0) is striking if one considers that it has empty d-orbitals at its disposal and contains, at the same time, no less than twenty H-atoms available for either α- or ß-hydride elimination.