Redox Isomerism in the S₃ State of the Oxygen-Evolving Complex Resolved by Coupled Cluster Theory.

ABSTRACT: The electronic and geometric structures of the water-oxidizing complex of photosystem II in the steps of the catalytic cycle that precede dioxygen evolution remain hotly debated. Recent structural and spectroscopic investigations support contradictory redox formulations for the active-site Mn₄ CaO_x cofactor in the final metastable S₃ state. These range from the widely accepted Mn^IV ₄ oxo-hydroxo model, which presumes that O-O bond formation occurs in the ultimate transient intermediate (S₄ ) of the catalytic cycle, to a Mn^III ₂ Mn^IV ₂ peroxo model representative of the contrasting "early-onset" O-O bond formation hypothesis. Density functional theory energetics of suggested S₃

SUBMITTER: Drosou M 

PROVIDER: S-EPMC8518824 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature