Electronic structure of hemin in solution studied by resonant X-ray emission spectroscopy and electronic structure calculations

J Phys Chem B. 2014 Aug 21;118(33):9938-43. doi: 10.1021/jp505129m. Epub 2014 Aug 6.

Abstract

Resonant inelastic X-ray scattering spectra at the iron L-edge from hemin in dimethyl sulfoxide liquid solution are reported. Our experiments, which are interpreted with the help of electronic structure calculations, support earlier assignments of hemin-solvent interactions, including the iron spin state and the role of the chloride ligand obtained from a total fluorescence yield study. The analysis of the explicit radiative relaxation channels of 2p core-level excited iron, explored in the present work, allows for a rather quantitative assignment of the orbitals involved in the excitation-deexcitation process of the core-excited hemin in solution. We specifically distinguish between contributions of partially and fully occupied valence orbitals to the broad X-ray emission band. In addition, our calculations reveal a detailed picture of the character of these orbitals.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chlorides / chemistry
  • Electrons
  • Ferrous Compounds / chemistry
  • Hemin / chemistry*
  • Hemin / metabolism
  • Quantum Theory
  • Solutions / chemistry
  • Spectrometry, X-Ray Emission*

Substances

  • Chlorides
  • Ferrous Compounds
  • Solutions
  • Hemin