X-ray Spectroscopic Study of the Electronic Structure of a Trigonal High-Spin Fe(IV)═O Complex Modeling Non-Heme Enzyme Intermediates and Their Reactivity.

Autor:	Braun A; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Gee LB; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Mara MW; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Hill EA; Department of Chemistry, University of California, Irvine, California 92697, United States., Kroll T; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Nordlund D; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Sokaras D; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Glatzel P; ESRF-The European Synchrotron Radiation Facility, 71 Avenue des Martyrs, Grenoble 38000, France., Hedman B; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Hodgson KO; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States., Borovik AS; Department of Chemistry, University of California, Irvine, California 92697, United States., Baker ML; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States.; Department of Chemistry, The University of Manchester, Manchester M13 9PL, U.K.; The University of Manchester at Harwell, Diamond Light Source, Harwell Campus, Didcot OX11 0DE, U.K., Solomon EI; Department of Chemistry, Stanford University, Stanford, California 94305, United States.; Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, California 94025, United States.
Jazyk:	angličtina
Zdroj:	Journal of the American Chemical Society [J Am Chem Soc] 2023 Aug 30; Vol. 145 (34), pp. 18977-18991. Date of Electronic Publication: 2023 Aug 17.
DOI:	10.1021/jacs.3c06181
Abstrakt:	Fe K-edge X-ray absorption spectroscopy (XAS) has long been used for the study of high-valent iron intermediates in biological and artificial catalysts. 4p-mixing into the 3d orbitals complicates the pre-edge analysis but when correctly understood via 1s2p resonant inelastic X-ray scattering and Fe L-edge XAS, it enables deeper insight into the geometric structure and correlates with the electronic structure and reactivity. This study shows that in addition to the 4p-mixing into the 3d z 2 orbital due to the short iron-oxo bond, the loss of inversion in the equatorial plane leads to 4p mixing into the 3d x 2 - y 2 , xy , providing structural insight and allowing the distinction of 6- vs 5-coordinate active sites as shown through application to the Fe(IV)═O intermediate of taurine dioxygenase. Combined with O K-edge XAS, this study gives an unprecedented experimental insight into the electronic structure of Fe(IV)═O active sites and their selectivity for reactivity enabled by the π-pathway involving the 3d xz / yz orbitals. Finally, the large effect of spin polarization is experimentally assigned in the pre-edge (i.e., the α/β splitting) and found to be better modeled by multiplet simulations rather than by commonly used time-dependent density functional theory.
Databáze:	MEDLINE
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