FIGURE 5.

XAS analysis of Fe/Fe and Mn/Fe centers in R2lox. Spectra at the iron (left) or manganese (right) K-edges of anaerobically reconstituted, reduced (red), aerobically reconstituted, x-ray photoreduced (xpr) and aerobically reconstituted, oxidized (ox) samples are shown (xpr denotes x-ray irradiation for ∼90 min, Fe/Fe center, or ∼50 min, Mn/Fe center, prior to the collection of the spectra). A, XANES spectra. Insets, iron or manganese K-edge energies (dots) for increasing x-ray irradiation periods determined from respective XANES spectra (data not shown) together with single exponential decay simulations (lines) with half-times of ∼33 min (iron) or ∼16 min (manganese). B, FTs of iron and manganese EXAFS oscillations in the insets (black lines, experimental data; colored lines, simulations with parameters in Table 4). Spectra are vertically displaced for comparison.