Preparation, UV–Vis, IR and 1H NMR spectra, and molecular structure of the complex ion (η2-carbonato)(α,α,α,α-tetrakis (o-pivalamidophenyl)porphinato)ferrate(III)

An iron(III) porphyrin complex containing a bidentate carbonato axial ligand has been synthesized for the first time and fully characterized by UV–Vis, IR and 1H NMR spectroscopies and X-ray crystallography. Proton NMR data for the isolated species is in accordance with high-spin (S = 5/2) ferric derivative. The crystal structure of the (cryptand-222)potassium(+) (dihaptocarbonato)(α,α,α,α-terakis(o-pivalamidophenyl)(porphinato)ferrate(III) chlorobenzene has been determined. This structure confirms the high-spin-state of the carbonato derivative and shows that the coordination sphere of the iron atom is strongly affected by the asymmetric bidentate (η2) mode of the carbonato axial ligand.