title: Electronic structure analysis of iron(III)-porphyrin complexes by X-ray absorption spectra at the C, N and Fe K-edges.
abstract: X-ray absorption near edge structure (XANES) measurements at the C, N, and Fe K absorption edges were performed for iron(III)-tetraphenylporphyrin (FeTPP), iron(III)-tetrakis(p-carboxyphenyl)porphyrin (FeTCPP), and iron(III)-tetrakis(p-sulfonatophenyl)porphyrin (FeTSPP). The spectral shapes differ in the Fe K XANES, but not in C and N K XANES among FeTPP, FeTCPP, and FeTSPP. Crosschecks of XANES data for C, N, and Fe K absorption edges in combination with discrete variational (DV)-Xalpha molecular orbital (MO) calculations indicate that each p-electron-withdrawing group on four meso-phenyl substitutes in an Fe(III)-porphyrin complex brings about a unique electron state through the complex because of the electron-withdrawal strength, itself. Consequently, they affect the positive charge of the center Fe(III) ion.
authors.affiliation: Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Yamashige
authors.forename: Shuji
authors.initials: S
authors.lastname: Matsuo
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Kurisaki
authors.forename: Rupert C C
authors.initials: RC
authors.lastname: Perera
authors.forename: Hisanobu
authors.initials: H
authors.lastname: Wakita
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D002244:Carbon / Q000737:chemistry*; D004583:Electrons; D007501:Iron / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D015394:Molecular Structure; D009584:Nitrogen / Q000737:chemistry*
chemical_list: D008665:Metalloporphyrins; C510470:iron(III)-tetrakis(p-carboxyphenyl)porphyrin; C510472:iron(III)-tetrakis(p-sulfonatophenyl)porphyrin; C510466:iron(III)-tetraphenylporphyrin; D002244:Carbon; D007501:Iron; D009584:Nitrogen