Magnetic and Electronic Structural Properties of the S₃ State of Nature's Water Oxidizing Complex: A Combined Study in ELDOR-Detected Nuclear Magnetic Resonance Spectral Simulation and Broken-Symmetry Density Functional Theory.

ABSTRACT: ELDOR-detected nuclear magnetic resonance (EDNMR) spectral simulations combined with broken-symmetry density functional theory (BS-DFT) calculations are used to obtain and to assign the ⁵⁵Mn hyperfine coupling constants (hfcs) for modified forms of the water oxidizing complex in the penultimate S₃ state of the water oxidation cycle. The study shows that an open cubane form of the core Mn₄CaO₆ cluster explains the magnetic properties of the dominant S = 3 species in all cases studied experimentally with no need to invoke a closed cubane intermediate possessing a distorted pentacoordinate Mn₄ ion as recently suggested. EDNMR simulations found that both the experimental bandwidth and multinuclear transitions may alter relative EDNM

SUBMITTER: Rogers CJ 

PROVIDER: S-EPMC9670293 | biostudies-literature | 2022 Nov

REPOSITORIES: biostudies-literature