Computational Electrochemistry as a Reliable Probe of Experimentally Elusive Mononuclear Nonheme Iron Species

Despite the growing number of reported FeIVO complexes, an unambiguous experimental characterization of their redox properties, such as one-electron reduction potentials, remains a challenging task. To this aim, we describe an efficient and straightforward theoretical protocol for accurate calculations of redox potentials and calibrate the protocol on a set of diverse 37 mononuclear nonheme iron (NHFe) redox couples. It is shown that the methodology, further applied to a set of 10 FeIVO species, not only serves for near-quantitative predictions of reduction potentials, but also is an elegant tool for interpretation of the experimental electrochemical data. The general need for such a computational methodology is illustrated on the prototypical example of the (N4Py)­FeIVO complex, whose electrochemistry has been studied for many years and still raises many questions.