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Role of redox-inactive metals in controlling the redox potential of heterometallic manganese-oxido clusters.

ABSTRACT: Photosystem II (PSII) contains Ca²⁺, which is essential to the oxygen-evolving activity of the catalytic Mn₄CaO₅ complex. Replacement of Ca²⁺ with other redox-inactive metals results in a loss/decrease of oxygen-evolving activity. To investigate the role of Ca²⁺ in this catalytic reaction, we investigate artificial Mn₃[M]O₂ clusters redox-inactive metals [M] ([M] = Mg²⁺, Ca²⁺, Zn²⁺, Sr²⁺, and Y³⁺), which were synthesized by Tsui et al. (Nat Chem 5:293, 2013). The experimentally measured redox potentials (E_m) of these clusters are best described by the energy of their highest occupied molecular orbitals. Quantum chemical calculations showed that the valence of metals predominantly affects E_m(Mn^III/IV), whereas the ionic radius of metals affects E_m(Mn^III/IV) only slightly.

SUBMITTER: Saito K

PROVIDER: S-EPMC8292285 | biostudies-literature |

REPOSITORIES: biostudies-literature

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