Solution and solid state characterization of oxo-centered trinuclear iron(III) acetate complexes [Fe3(μ3-O)(μ-OAc)6(L)3]+

[Fe3(μ3-O)(μ-OAc)6(py)3][FeBr4]2[py·H], complex (1), (OAc is acetate) was prepared from the reaction of FeBr3 with pyridine in 1.2 molar aqueous HBr and 2.4 molar aqueous CH3COOH. Recrystallization of 1 in acetonitrile produced the [Fe3(μ3-O)(μ-OAc)6(py)3][FeBr4] complex (2). Both complexes were characterized by IR and 1H NMR spectroscopies and their structures were studied using the single-crystal diffraction method. There is a lack of thorough characterization of the titled compounds in solution. Paramagnetic 1H NMR is introduced as a good probe for the characterization of a family of titled compounds in solution when the L ligand coordinated to iron varies as: CH3OH, CH3CN, DMSO, H2O, py and acetone.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Trinuclear oxo-centered iron carboxylato complexes were synthesized. ► There is a lack of thorough characterization of the oxo-centered iron complexes in solution. ► Paramagnetic 1H NMR is introduced as a good probe for the characterization of a family of these complexes in solution. ► Ligand coordinated to iron varies as: CH3OH, CH3CN, DMSO, H2O, py and acetone in solution.