Iron(II) Corrole Anions.

Reduction of [Fe(TPC)(THF)] (TPC = trianion of 5,10,15-triphenylcorrole) with KC generates the iron(II) corrole anion, K(THF)[Fe(TPC)] (). Compound represents the first example of an isolated and crystallographically characterized corrole complex of divalent iron. The compound adopts an intermediate-spin state ( = 1), displaying square-planar geometry about the iron atom. All-electron density functional theory (OLYP and B3LYP) calculations with STO-TZP basis sets indicate two essentially equienergetic d electron configurations, dddd (occupation 1) and dddd (occupation 2), as likely contenders for the ground state of [Fe(TPC)], with the optimized geometry of the former in slightly better agreement with the low-temperature X-ray structure. Solutions of react with carbon monoxide to afford the low-spin ( = 0) complex, [Fe(TPC)(CO)], whereas introduction of oxygen at -78 °C leads to a putative O adduct, [Fe(TPC)(O)], which decays rapidly even at low temperatures. Treatment of with organic electrophiles results in formal oxidative addition to give both iron(III) and iron(IV) corrole species. With iodomethane, [Fe(TPC)Me] is produced, illustrating the first instance of alkyl ligand coordination in an iron corrole complex.