Metallkomplexe mit Tetrapyrrol-Liganden, XIV.

Abstract

An air-stable porphodimethene, namely α, γ-dimethyl-α, γ-dihydrooctaethylporphyrin [H 2 (OÄPMe 2 )*; (1)] is metalated with Fe(CO) 5 /I 2 in toluene to yield an air-stable binuclear iron(III) porphodimethene, μ-oxobis(α, γ-dimethyl-α, γ-dihydrooctaethylporphinato)iron-(III) [(OÄPMe 2 )FeOFe(OÄPMe 2 ); (2a)] after chromatography and crystallization. 2a is transformed into the mononuclear hemins Fe(OÄPMe 2 )X [X = OMe, OPh, OAc, Cl (2 b-2 e)] and into a nitrosyl heme Fe(OÄPMe 2 )NO (2f). Other hemes are identified in solution. The compounds are characterized by elemental analyses, electronic-, IR, and mass spectra. IR data and magnetic moments as measured in solution by the Evans method allow a distinction between the mononuclear and binuclear species. While the Fe II porphodimethenes (hemes) show only one strong absorption in the visible region λ≈460 nm; like Zn(OÄPMe 2 ), the Fe III species (hemins) have three characteristic strong bands (λ≈ 400, 450, and 540 nm for the μ-oxo species).