Electronic structure analysis of iron(III)-porphyrin complexes by X-ray absorption spectra at the C, N and Fe K-edges.
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.
Yamashige
Hisao
H
Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan.
Matsuo
Shuji
S
Kurisaki
Tsutomu
T
Perera
Rupert C C
RC
Wakita
Hisanobu
H
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*
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