title: One-electron oxidized product of difluoroiron(III) porphyrin: is it iron(IV) porphyrin or iron(III) porphyrin π-cation radical?
abstract: The electronic structure of [Fe(TMP)F(2)], which is formally a one-electron oxidation equivalent above [Fe(III)(TMP)F(2)](-), has been examined in solution by (1)H NMR, UV-Vis, and Mössbauer spectroscopy. In CD(2)Cl(2)-CD(3)OD solution at 193 K, the pyrrole-H and m-H signals appeared at 128.2 and 116.7 ppm, respectively. The UV-Vis spectrum showed broad absorption bands at 560-680 nm. The Mössbauer spectrum taken in frozen toluene-methanol solution exhibited a very broad single line from which the IS and QS values were determined by computer simulation to be 0.50 and 0.14 mm s(-1), respectively. On the basis of these results, it was concluded that the one-electron oxidized product of [Fe(TMP)F(2)](-) should be formulated as the iron(III) radical cation [Fe(III)(TMP˙)F(2)], not as iron(IV) porphyrin [Fe(IV)(TMP)F(2)] as previously suggested.
authors.affiliation: Department of Chemistry, School of Medicine, Toho University, Tokyo 143-8540, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Ikezaki
authors.forename: Masashi
authors.initials: M
authors.lastname: Takahashi
authors.forename: Mikio
authors.initials: M
authors.lastname: Nakamura
mesh_terms: D004583:Electrons; D054879:Halogenation; D058085:Iron Compounds / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010084:Oxidation-Reduction; D011166:Porphyrins / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet; D015204:Spectroscopy, Mossbauer
chemical_list: D058085:Iron Compounds; D011166:Porphyrins; C028565:porphyrin pi cation radical