CaMn₃ ^IV O₄ Cubane Models of the Oxygen-Evolving Complex: Spin Ground States S<9/2 and the Effect of Oxo Protonation.

ABSTRACT: We report the single crystal XRD and MicroED structure, magnetic susceptibility, and EPR data of a series of CaMn₃ ^IV O₄ and YMn₃ ^IV O₄ complexes as structural and spectroscopic models of the cuboidal subunit of the oxygen-evolving complex (OEC). The effect of changes in heterometal identity, cluster geometry, and bridging oxo protonation on the spin-state structure was investigated. In contrast to previous computational models, we show that the spin ground state of CaMn₃ ^IV O₄ complexes and variants with protonated oxo moieties need not be S=9/2. Desymmetrization of the pseudo-C₃ -symmetric Ca(Y)Mn₃ ^IV O₄ core leads to a lower S=5/2 spin ground sta

SUBMITTER: Lee HB 

PROVIDER: S-EPMC8319083 | biostudies-literature | 2021 Aug

REPOSITORIES: biostudies-literature