Synthesis, characterization and reactivity of a Mn(III)-hydroxido complex as a biomimetic model for lipoxygenase.

Autor: Phu PN; Department of Chemistry, University of California, Irvine, CA 92697, United States., Barman SK; Department of Chemistry, University of California, Irvine, CA 92697, United States; Department of Chemical Sciences, India Institute of Science Education and Research (IISER) Mohali, Manauli 140306, India., Ziller JW; Department of Chemistry, University of California, Irvine, CA 92697, United States., Hendrich MP; Department of Chemistry, Carnegie Mellon University, Pittsburgh, PA 15213, United States., Borovik AS; Department of Chemistry, University of California, Irvine, CA 92697, United States. Electronic address: aborovik@uci.edu.
Jazyk: angličtina
Zdroj: Journal of inorganic biochemistry [J Inorg Biochem] 2024 Oct; Vol. 259, pp. 112618. Date of Electronic Publication: 2024 Jun 12.
DOI: 10.1016/j.jinorgbio.2024.112618
Abstrakt: Manganese hydroxido (Mn-OH) complexes supported by a tripodal N,N',N″-[nitrilotris(ethane-2,1-diyl)]tris(P,P-diphenylphosphinic amido) ([poat] 3- ) ligand have been synthesized and characterized by spectroscopic techniques including UV-vis and electron paramagnetic resonance (EPR) spectroscopies. X-ray diffraction (XRD) methods were used to confirm the solid-state molecular structures of {Na 2 [Mn II poat(OH)]} 2 and {Na[Mn III poat(OH)]} 2 as clusters that are linked by the electrostatic interactions between the sodium counterions and the oxygen atom of the ligated hydroxido unit and the phosphinic (P=O) amide groups of [poat] 3- . Both clusters feature two independent monoanionic fragments in which each contains a trigonal bipyramidal Mn center that is comprised of three equatorial deprotonated amide nitrogen atoms, an apical tertiary amine, and an axial hydroxido ligand. XRD analyses of {Na[Mn III poat(OH)]} 2 also showed an intramolecular hydrogen bonding interaction between the Mn III -OH unit and P=O group of [poat] 3- . Crystalline {Na[Mn III poat(OH)]} 2 remains as clusters with Na + ---O interactions in solution and is unreactive toward external substrates. However, conductivity studies indicated that [Mn III poat(OH)] - generated in situ is monomeric and reactivity studies found that it is capable of cleaving C-H bonds, illustrating the importance of solution-phase speciation and its direct effect on chemical reactivity. Synopsis: Manganese-hydroxido complexes were synthesized to study the influence of H-bonds in the secondary coordination sphere and their effects on the oxidative cleavage of substrates containing C-H bonds.
Competing Interests: Declaration of competing interest The authors declare no conflict of interest.
(Copyright © 2024. Published by Elsevier Inc.)
Databáze: MEDLINE
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