Formation of an Aqueous Oxoiron(IV) Complex at pH 2-6 from a Nonheme Iron(II) Complex and H_2O_2

摘要

The oxidation chemistry of iron(II) in water has been discussed since the days of Fenton and his discovery of the ability of iron(II) salts together with hydrogen peroxide to oxidize organic substrates in acidic aqueous solutions.[1]-[3] The involvement of hydroxyl radicals[4] and/or iron(IV) species[5] has been suggested on the basis of experimental observations, and DFT calculations support the latter.[6] More recently, oxoiron(IV) intermediates have been identified in the catalytic cycle of taurine -ketoglutarate dioxygenase (TauD)[7], [8] and characterized for several synthetic nonheme complexes,[9]-[14] including two high-resolution crystal structures.[10], [13] On the basis of the spectroscopic signatures of these precedents, similar intermediates in other systems can be analyzed.