No abstract

Reactivities of non-heme iron(IV)-oxo complexes are mostly controlled by the ligands.C omplexes with tetradentate ligands such as [(TPA)FeO] 2+ (TPA = tris(2-pyridylmethyl)amine) belong to the most reactive ones.Here,weshow af ine-tuning of the reactivity of [(TPA)FeO] 2+ by an additional ligand X(X= CH 3 CN,CF 3 SO 3 À ,ArI, and ArIO;ArI = 2-(t BuSO 2)C 6 H 4 I) attached in solution and reveal at hus far unknown role of the ArIO oxidant. The HATr eactivity of [(TPA)FeO(X)] +/2+ decreases in the order of X: ArIO > MeCN > ArI % TfO À .Hence,ArIO is not just amere oxidant of the iron(II) complex, but it can also increase the reactivity of the iron(IV)-oxo complex as alabile ligand. The detected HAT reactivities of the [(TPA)FeO(X)] +/2+ complexes correlate with the Fe = Oand FeO À Hstretching vibrations of the reactants and the respective products as determined by infrared photodissociation spectroscopy. Hence,t he most reactive [(TPA)FeO-(ArIO)] 2+ adduct in the series has the weakest Fe=Obond and forms the strongest FeOÀHb ond in the HATreaction. Scheme 1. Iron(IV)-oxo complexes formed by oxidation of [(TPA)Fe II-(TfO) 2 ]w ith ArIO (ArI = 2-(t BuSO 2)C 6 H 4 I).

Reactivities of non‐heme iron(IV)‐oxo complexes are mostly controlled by the ligands. Complexes with tetradentate ligands such as [(TPA)FeO]2+ (TPA=tris(2‐pyridylmethyl)amine) belong to the most reactive ones. Here, we show a fine‐tuning of the reactivity of [(TPA)FeO]2+ by an additional ligand X (X=CH3CN, CF3SO3−, ArI, and ArIO; ArI=2‐(tBuSO2)C6H4I) attached in solution and reveal a thus far unknown role of the ArIO oxidant. The HAT reactivity of [(TPA)FeO(X)]+/2+ decreases in the order of X: ArIO > MeCN > ArI ≈ TfO−. Hence, ArIO is not just a mere oxidant of the iron(II) complex, but it can also increase the reactivity of the iron(IV)‐oxo complex as a labile ligand. The detected HAT reactivities of the [(TPA)FeO(X)]+/2+ complexes correlate with the Fe=O and FeO−H stretching vibrations of the reactants and the respective products as determined by infrared photodissociation spectroscopy. Hence, the most reactive [(TPA)FeO(ArIO)]2+ adduct in the series has the weakest Fe=O bond and forms the strongest FeO−H bond in the HAT reaction.

No abstract