Inorganic Chemistry, Vol.59, No.24, 18141-18155, 2020
Insights into Molecular Magnetism in Metal-Metal Bonded Systems as Revealed by a Spectroscopic and Computational Analysis of Diiron Complexes
A pair of bimetallic compounds featuring FeFe bonds, [Fe((PrNPPh2)-Pr-i)(3)FeR] (R = PMe3, =(NBu)-Bu-t), have been investigated using High-Frequency Electron Paramagnetic Resonance (HFEPR) as well as field- and temperature-dependent Fe-57 nuclear gamma resonance (Mossbauer) spectroscopy. To gain insight into the local site electronic structure, we have concurrently studied a compound containing a single Fe(II) in a geometry analogous to that of one of the dimer sites. Our spectroscopic studies have allowed for the assessment of the electronic structure via the determination of the zero-field splitting and Fe-57 hyperfine parameters for the entire series. We also report on our efforts to correlate structure with physical properties in metalmetal bonded systems using ligand field theory guided by quantum chemical calculations. Through the insight gained in this study, we discuss strategies for the design of single-molecule magnets based on polymetallic compounds linked via direct metalmetal bonds.