Figure 11.

a) EPR spectra recorded at 77 K of generated phenoxyl radicals by the reaction of [DCHIm(F₈)Fe^III-(O₂^2-)-Cu^II(AN)]⁺ (2b) and 2,4,6-tri-tert-butylphenol (A) or 2,4-di-tert-butyl-4-methoxylphenol (B) at -80° C in THF. As determined in separate experiments, at equal concentrations of a phenoxyl radical with a copper(II) complex, the radical g ~ 2 signal peak intensity is vastly greater than the peak intensities for the g ~ 2.0-to-2.3 signals resultant from the copper(II) ion due to the differences in peak width, which is why the latter is essentially not observable. Also, within the resolution of the EPR experiments conducted, the g-values are indistinguishable.⁹⁰,⁹¹ b) UV-vis monitoring of the reaction of 2b with 2,4-di-tert-butyl-phenol at -80° C.