Crystal Structure Analysis of a Synthetic Non‐Heme DiironO₂ Adduct: Insight into the Mechanism of Oxygen Activation

The enhanced stability provided by two triphenylphosphane oxide ligands has enabled the first crystal structure analysis of a non-heme diironO2 adduct (1) (structure of the core is shown on the right). Complexes of this type can be activated by introducing a more electron-donating carboxylate ligand. These observations rationalize the carboxylate-rich active sites of non-heme diiron oxygen-activating enzymes such as methane monooxygenase and ribonucleotide reductase. [Fe2(μ-1,2,O2)(N-Et-hptb)(Ph3PO)2](BF4)3 1