Biomimetic Peroxo- and Oxo-manganese Complexes: Insights into Structure and Reactivity through Kinetic, Spectroscopic, and Computational Studies

Abstract

Manganese centers that react with O2 and its reduced derivatives mediate a diverse array of biologically important reactions including the detoxification of superoxide, the conversion of nucleotides to deoxynucleotides, and the generation of O2 from H2O. Peroxo-, oxo-, and hydroxo-manganese motifs are frequently invoked in the catalytic cycles of Mn enzymes. To that end, biomimetic complexes featuring peroxo-, oxo-, and hydroxo-manganese adducts were synthesized and studied using spectroscopic techniques, including variable-temperature electronic absorption, electron paramagnetic resonance (EPR), X-ray absorption (XAS), and magnetic circular dichroism (MCD) spectroscopies along with computational methods, such as density functional theory (DFT) and time-dependent DFT. The structural and spectroscopic properties of these species were investigated in order to better understand how the geometric and electronic structure of these complexes affects reactivity.