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We report a rare example of oxygen atom transfer (OAT) from a polyoxometalate cluster to a series of tertiary phosphanes. Addition of PR 3 (PR 3 = PMe 3 , PMe 2 Ph, PMePh 2 , PPh 3 ) to a neutral methoxide-bridged polyoxovanadate-alkoxide (POV-alkoxide) cluster, [V 6 O 7 (OMe) 12 ] 0 , results in isolation of a reduced structure with phosphine oxide datively coordinated to a site-differentiated V III ion. A positive correlation between the steric and electronic properties of the phosphane and the reaction rate was observed. Further investigation of the steric influence of the alkoxy-bridged clusters on OAT was probed through the use of POV clusters with bridging alkoxide ligands of varying chain length ([V 6 O 7 (OR′) 12 ]; R′ = Et, n Pr). These investigations expose that steric hinderance of the vanadyl moieties has significant influence on the rate of OAT. Finally, we report the reactivity of the reduced POV-alkoxide clusters with styrene oxide, resulting in the deoxygenation of the substrate to generate styrene. This result is the first example of epoxide deoxygenation using homometallic polyoxometalate clusters, demonstrating the potential for mono-vacant Lindqvist clusters to catalyze the removal of oxygen atoms from organic substrates.
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This content will become publicly available on February 19, 2026
Isolation of a Rare Terminal Zr(IV) Peroxide and Insight into Polyoxovanadate Support Impact on Thioether Oxidation
Abstract Substitutional lability of the terminal methoxide ligand on a Zr(IV) substituted polyoxovanadate‐alkoxide (POV‐alkoxide) via protonolysis is presented. Addition of excess water or stoichiometric 2,2,2‐trifluoroethanol results in the exchange of the terminal methoxide ligand for a hydroxide or 2,2,2‐trifluoroethoxide ligand, respectively. The lability of the terminal methoxide ligand at zirconium is leveraged to access a relatively stable terminal peroxide bound to a POV‐alkoxide supported Zr(IV) center, via addition of hydrogen peroxide adducts compatible with organic solvent. Isolation of the terminal peroxide complex allows for investigation into the impact of the sterically protected, electron‐rich POV‐alkoxide support on the activation of hydrogen peroxide at Zr(IV). While the isolated peroxide complex is inactive towards the oxidation of thioethers, the methoxy terminated Zr(IV) functions as a precatalyst for the reaction. Mechanistic analysis reveals electrophilic oxidation conditions with hydrogen peroxide substrates, with a nucleophilic parameter ( ) of 0.09±0.02. In thioether oxidation reactions, selectivity for sulfoxide products (95–99 %) in acetonitrile is observed, suggesting the use of a reduced POV‐alkoxide prevents over‐oxidation of substrate.
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- Award ID(s):
- 2154727
- PAR ID:
- 10577068
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Chemistry – A European Journal
- Volume:
- 31
- Issue:
- 20
- ISSN:
- 0947-6539
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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