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.

The present work reports the synthesis, the spectroscopic data and the crystal structure of the high-spin iron(III) η2-carbonato picket fence porphyrin complex [K(2,2,2-crypt)][FeIII(TpivPP) (η2-O2CO)] · C6H5Cl (TpivPP = α,α,α,α-tetrakis(o-pivalamidophenyl)porphinato and 2,2,2-crypt is the cryptand-222). Proton NMR data for the isolated species is in accordance with high-spin (S = 5/2) ferric derivative. The molecular structure shows that the coordination sphere of the iron atom is strongly affected by the asymmetric bidentate (η2) mode of the carbonato axial ligand.Figure optionsDownload as PowerPoint slide