High-valent nonheme iron-oxo complexes: Synthesis, structure, and spectroscopy

High-valent iron-oxo intermediates have often been implicated, and in some cases identified, as the active oxidant in oxygen activating nonheme iron enzymes. Recent synthetic efforts have yielded pivotal insights into the generation of oxoiron(IV and V) complexes, and allowed thorough investigation of their spectroscopic, structural, and electronic properties. Furthermore, insight into the mechanisms by which nonheme iron sites activate dioxygen to yield high valent iron-oxo intermediates has been obtained. This review covers the great successes in iron-oxo chemistry over the past decade, detailing various efforts to obtain iron-oxo complexes in high yield, and to delve into their diverse structural and spectroscopic properties.