Unusual Dinitrogen Binding and Electron Storage in Dinuclear Iron Complexes.

摘要: A rare example of a dinuclear iron core with non-linearly bridged dinitrogen ligand is reported in this work. One-electron reduction [(tBupyrr2py)Fe(OEt2)] (1) (tBupyrr2py2- = 2,6-bis((3,5-di-tert-butyl)pyrrol-2-yl)pyridine) KC8 yields the complex [K]2[(tBupyrr2py)Fe]2(μ2-η1:η1-N2) (2), where unusual cis-divacant octahedral coordination geometry about each and η5-cation-π two potassium ions four pyrrolyl units cause distortion bridging end-on μ-N2 FeN2Fe core. Attempts to generate Et2O-free version 1 resulted instead helical dimer, [(tBupyrr2py)Fe]2 (3), via pyridine moieties ligand. Reduction 3 by electrons under N2 does not break up nor it result formation 2 but ate-complex [K(OEt2)]2[(tBupyrr2py)Fe]2 (4). presence crown-ether forms tetraanionic [K2][K(18-crown-6)]2(tBupyrr2py)Fe]2(μ2-η1:η1-N2) (5), also having distorted moiety akin 2. Complex thermally unstable loses N2, disproportionating Fe nanoparticles among other products. combination single-crystal X-ray diffraction studies, solution solid-state magnetic 57Fe Mossbauer spectroscopy has been applied characterize complexes 2-5, whereas DFT studies have used help explain bonding electronic structure these unique diiron-N2 5.