Modeling
TauD‑<i><b>J</b></i>: A High-Spin Nonheme Oxoiron(IV)
Complex with High Reactivity toward
C–H Bonds
- Publication date
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Abstract
High-spin oxoiron(IV) species are
often implicated in the mechanisms
of nonheme iron oxygenases, their C–H bond cleaving properties
being attributed to the quintet spin state. However, the few available
synthetic <i>S</i> = 2 Fe<sup>IV</sup>O complexes
supported by polydentate ligands do not cleave strong C–H bonds.
Herein we report the characterization of a highly reactive <i>S</i> = 2 complex, [Fe<sup>IV</sup>(O)(TQA)(NCMe)]<sup>2+</sup> (<b>2</b>) (TQA = tris(2-quinolylmethyl)amine), which oxidizes
both C–H and CC bonds at −40 °C. The oxidation
of cyclohexane by <b>2</b> occurs at a rate comparable to that
of the oxidation of taurine by the TauD-<i><b>J</b></i> enzyme intermediate after adjustment for the different temperatures
of measurement. Moreover, compared with other <i>S</i> =
2 complexes characterized to date, the spectroscopic properties of <b>2</b> most closely resemble those of TauD-<i><b>J</b></i>. Together these features make <b>2</b> the best electronic <i>and</i> functional model for TauD-<i><b>J</b></i> to date
