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Protein Film Infrared Electrochemistry Demonstrated for Study of H2 Oxidation by a [NiFe] Hydrogenase
Published on: December 4, 2017
A computational analysis of electromerism in hemoprotein Fe(I) models
Radu Silaghi-Dumitrescu1, Sergei V Makarov
1Department of Chemistry and Chemical Engineering, Babes-Bolyai University, Cluj-Napoca, 400028, Romania. rsilaghi@chem.ubbcluj.ro
Summary
Density functional theory reveals electromerism in iron-sulfur and iron-imidazole hemoproteins. Electronic structures shift between iron(II) and iron(III) states, influenced by ligands and spin states.
Area of Science:
- Computational chemistry
- Bioinorganic chemistry
Background:
- Hemoproteins contain iron centers crucial for various biological functions.
- Understanding the electronic structure of iron centers is key to elucidating their reactivity.
Purpose of the Study:
- To investigate the electronic structures of formally Fe(I) centers in thiolate- and imidazole-ligated hemoproteins.
- To explore the phenomenon of electromerism in these systems.
Main Methods:
- Density functional theory (DFT) calculations were employed.
- Analysis of spin states and electron distribution within the hemoprotein models.
Main Results:
- Electromerism was observed, with electronic structures fluctuating between Fe(II) and Fe(III) states.
- Spin density analysis revealed complex electronic configurations, including antiferromagnetic coupling to porphyrin triplet states.
- Axial ligand identity, iron-ligand bond length, and overall spin state were identified as key factors influencing electromerism.
Conclusions:
- The electronic structures of formally Fe(I) hemoproteins exhibit electromerism, challenging simple oxidation state assignments.
- DFT provides insights into the nuanced electronic behavior of iron centers in hemoproteins.
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