Heidelberg 2015 – wissenschaftliches Programm

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MO: Fachverband Molekülphysik

MO 16: Posters 3: Novelties in Molecular Physics

MO 16.1: Poster

Mittwoch, 25. März 2015, 17:00–19:00, C/Foyer

X-ray spectra of hemin in different solvents: theoretical approach — •Marie Preuße, Sergey I. Bokarev, and Oliver Kühn — Institut für Physik, Universität Rostock, 18051 Rostock

Metalloporphyrins are essential constituents of a variety of enzyme active centers and are important due to their catalytic activity and biological functions. Hemin, being one example, is of particular interest as it is the chlorine salt of the heme group, which is known to play a major role in the oxygen storage and transport in living beings. X-ray spectroscopic methods are a powerful tool to probe the local electronic structure. They have been used in previous investigations to derive the spin state of hemin and hemoglobin in physiological solution by Aziz et al. [1]
Recently, resonant X-ray absorption (XAS) and inelastic scattering (RIXS) spectra of hemin in DMSO and in water have been reported [2]. Hemin is known to form dimers in water solutions, staying monomeric in other solvents [3]. In the present work we address the fingerprints of dimerization in water solution in XAS and RIXS using Restricted Active Space SCF and State Interaction computational methods (RASSCF/RASSI). Thereby we take into account strong correlation effects as well as spin-orbit coupling.

[1] Emad F. Aziz et al. Phys. Rev. Lett., 102:068103-1, 2009.
[2] Kaan Atak et al. J. Phys. Chem. B, 118(33):9938, 2014
[3] Katherine A. de Villiers et al. JBIC, 12(1):101, 2007