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Unusual Dinitrogen Binding and Electron Storage in Dinuclear Iron Complexes
- Source :
- Journal of the American Chemical Society, Journal of the American Chemical Society, American Chemical Society, 2020, 142 (18), pp.8147-8159. ⟨10.1021/jacs.0c01488⟩
- Publication Year :
- 2020
- Publisher :
- American Chemical Society (ACS), 2020.
-
Abstract
- A rare example of a dinuclear iron core with a non-linearly bridged dinitrogen ligand is reported in this work. One-electron reduction of [(tBupyrr2py)Fe(OEt2)] (1) (tBupyrr2py2- = 2,6-bis((3,5-di-tert-butyl)pyrrol-2-yl)pyridine) with KC8 yields the complex [K]2[(tBupyrr2py)Fe]2(μ2-η1:η1-N2) (2), where the unusual cis-divacant octahedral coordination geometry about each iron and the η5-cation-π coordination of two potassium ions with four pyrrolyl units of the ligand cause distortion of the bridging end-on μ-N2 about the FeN2Fe core. Attempts to generate a Et2O-free version of 1 resulted instead in a dinuclear helical dimer, [(tBupyrr2py)Fe]2 (3), via bridging of the pyridine moieties of the ligand. Reduction of 3 by two electrons under N2 does not break up the dimer, nor does it result in formation of 2 but instead formation of the ate-complex [K(OEt2)]2[(tBupyrr2py)Fe]2 (4). Reduction of 1 by two electrons and in the presence of crown-ether forms the tetraanionic N2 complex [K2][K(18-crown-6)]2(tBupyrr2py)Fe]2(μ2-η1:η1-N2) (5), also having a distorted FeN2Fe moiety akin to 2. Complex 2 is thermally unstable and loses N2, disproportionating to Fe nanoparticles among other products. A combination of single-crystal X-ray diffraction studies, solution and solid-state magnetic studies, and 57Fe Mossbauer spectroscopy has been applied to characterize complexes 2-5, whereas DFT studies have been used to help explain the bonding and electronic structure in these unique diiron-N2 complexes 2 and 5.
- Subjects :
- Chemistry
Dimer
Nanoparticle
General Chemistry
Electronic structure
[CHIM.INOR]Chemical Sciences/Inorganic chemistry
010402 general chemistry
01 natural sciences
Biochemistry
Catalysis
0104 chemical sciences
3. Good health
Crystallography
chemistry.chemical_compound
Colloid and Surface Chemistry
Octahedron
Mössbauer spectroscopy
Pyridine
Moiety
ComputingMilieux_MISCELLANEOUS
Coordination geometry
Subjects
Details
- ISSN :
- 15205126 and 00027863
- Volume :
- 142
- Database :
- OpenAIRE
- Journal :
- Journal of the American Chemical Society
- Accession number :
- edsair.doi.dedup.....1c84db5f68081207cd6662da25759a37