57 Fe nuclear resonance vibrational spectroscopic studies of tetranuclear iron clusters bearing terminal iron(iii)-oxido/hydroxido moieties.

Autor: Xiong J; Department of Chemistry, Carnegie Mellon University Pittsburgh PA 15213 USA ysguo@andrew.cmu.edu., Reed C; Division of Chemistry and Chemical Engineering, California Institute of Technology CA 91125 USA agapie@caltech.edu., Lavina B; Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA.; Center for Advanced Radiation Source, University of Chicago Chicago Illinois 60439 USA., Hu MY; Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA., Zhao J; Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA., Alp EE; Advanced Photon Source, Argonne National Laboratory Argonne Illinois 60439 USA., Agapie T; Division of Chemistry and Chemical Engineering, California Institute of Technology CA 91125 USA agapie@caltech.edu., Guo Y; Department of Chemistry, Carnegie Mellon University Pittsburgh PA 15213 USA ysguo@andrew.cmu.edu.
Jazyk: angličtina
Zdroj: Chemical science [Chem Sci] 2024 Sep 09. Date of Electronic Publication: 2024 Sep 09.
DOI: 10.1039/d4sc03396e
Abstrakt: 57 Fe nuclear resonance vibrational spectroscopy (NRVS) has been applied to study a series of tetranuclear iron ([Fe 4 ]) clusters based on a multidentate ligand platform (L 3- ) anchored by a 1,3,5-triarylbenzene linker and pyrazolate or ( tert butylamino)pyrazolate ligand (PzNH t Bu - ). These clusters bear a terminal Fe(iii)-O/OH moiety at the apical position and three additional iron centers forming the basal positions. The three basal irons are connected with the apical iron center via a μ 4 -oxido ligand. Detailed vibrational analysis via density functional theory calculations revealed that strong NRVS spectral features below 400 cm -1 can be used as an oxidation state marker for the overall [Fe 4 ] cluster core. The terminal Fe(iii)-O/OH stretching frequencies, which were observed in the range of 500-700 cm -1 , can be strongly modulated (energy shifts of 20-40 cm -1 were observed) upon redox events at the three remote basal iron centers of the [Fe 4 ] cluster without the change of the terminal Fe(iii) oxidation state and its coordination environment. Therefore, the current study provides a quantitative vibrational analysis of how the remote iron centers within the same iron cluster exert exquisite control of the chemical reactivities and thermodynamic properties of the specific iron site that is responsible for small molecule activation.
Competing Interests: There are no conflicts to declare.
(This journal is © The Royal Society of Chemistry.)
Databáze: MEDLINE
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