Abstract
The iron oxo unit, [Fe=O] (n+) is a critical intermediate in biological oxidation reactions. While its higher oxidation states are well studied, relatively little is known about the least-oxidized form [Fe(III)=O](+). Here, the thermally stable complex PhB(AdIm)(3)Fe=O has been structurally, spectroscopically, and computationally characterized as a bona fide iron(III) oxo. An unusually short Fe-O bond length is consistent with iron-oxygen multiple bond character and is supported by electronic structure calculations. The complex is thermally stable yet is able to perform hydrocarbon oxidations, facilitating both C-O bond formation and dehydrogenation reactions.