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Biologically relevant heterodinuclear iron-manganese complexes
Michaël Carboni1, Martin Clémancey, Florian Molton
1Laboratoire de Chimie et Biologie des Métaux-pmb, UMR 5249, Université Joseph Fourier-Grenoble 1/CEA-DSV-iRTSV/CNRS, Grenoble F-38054, France.
Inorganic Chemistry
|September 20, 2012
Summary
Synthesized iron-manganese complexes model nonheme enzymes, revealing antiferromagnetic interactions between metal ions. These findings offer insights into the electronic structure of biologically relevant iron-manganese enzyme active sites.
Area of Science:
- Bioinorganic Chemistry
- Coordination Chemistry
- Enzyme Mimicry
Background:
- Nonheme iron and manganese enzymes play crucial biological roles.
- Understanding the active sites of these enzymes is essential for elucidating their mechanisms.
- Heterodinuclear complexes serve as valuable models for studying metalloenzyme active sites.
Purpose of the Study:
- To synthesize and characterize novel heterodinuclear iron-manganese complexes.
- To model the active sites of the Fe/Mn class of nonheme enzymes.
- To investigate the magnetic and electronic properties of these model complexes.
Main Methods:
- Synthesis and characterization of heterodinuclear complexes [Fe(III)Mn(II)(L-Bn)(μ-OAc)(2)](ClO(4))(2) and [Fe(II)Mn(II)(L-Bn)(μ-OAc)(2)](ClO(4)).
- X-ray crystallography for structural determination of compound 1.
- Mössbauer spectroscopy, 1H NMR spectroscopy, magnetic susceptibility measurements, and electron paramagnetic resonance (EPR) studies.
Main Results:
- Structural elucidation revealed an Fe(III)Mn(II)μ-phenoxobis(μ-carboxylato) core.
- Mössbauer and NMR spectroscopies confirmed the single location of Fe(III) and Fe(II) ions, respectively.
- Moderate to weak antiferromagnetic interactions were observed between Fe and Mn ions (J = 20 cm(-1) for complex 1, J = 5.72-6.8 cm(-1) for complex 2).
- Electrochemical studies showed a quasireversible electron transfer corresponding to the Fe(III)Mn(II)/Fe(II)Mn(II) couple.
Conclusions:
- The synthesized complexes effectively model the biologically relevant Fe/Mn nonheme enzyme active sites.
- The study provides detailed insights into the magnetic coupling and electronic structure of these dinuclear systems.
- The findings contribute to a deeper understanding of the structure-function relationships in iron-manganese metalloenzymes.
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