Journal article
O-2 Activation with a Sterically Encumbered, Oxygen-Deficient Polyoxovanadate-Alkoxide Cluster
Inorganic chemistry, Vol.60(18), pp.13833-13843
09/20/2021
DOI: 10.1021/acs.inorgchem.1c00887
PMID: 34161731
Abstract
The isolation of the oxygen-deficient, polyoxovanadate-alkoxide (POV-alkoxide) cluster, [(Bu4N)-Bu-n][V6O6(OMe)(12)(MeCN)], and its subsequent reactivity with oxygen (O-2), has demonstrated the utility of these assemblies as molecular models for heterogeneous metal oxide catalysts. However, the mechanism through which this cluster activates and reduces O-2 to generate the oxygenated species is poorly understood. Currently it is speculated that this POV-alkoxide mediates the four-electron O-O bond cleavage through an O-2 bridged dimeric intermediate, a mechanism which is not viable for O-2 reduction at solid-state metal oxide surfaces. Here, we report the successful activation and reduction of O-2 by the calix-functionalized POV-alkoxide cluster, [(Bu4N)-Bu-n][(calix)V6O6(OMe)(8)](MeCN)] (calix = 4-tert-butylcalix[4]arene). The steric hindrance imparted to the open vanadium site by the calix motif eliminates the possibility of cooperative, bimolecular O-2 activation, allowing for a comparison of the reactivity of this system with that of the nonfunctionalized POV-alkoxide described previously. Rigorous characterization of the calix-substituted assembly, enabled by its newfound solubility in organic solvent, reveals that the incorporation of the tetradentate aryloxide ligand into the POV-alkoxide scaffold perturbs the electronic communication between the site-differentiated vanadium(III) ion and the cluster core. Collectively, our results provide insight into the physiochemical factors that are important during the O-2 reduction reaction at oxygen-deficient sites in reduced POV-alkoxide clusters.
Details
- Title: Subtitle
- O-2 Activation with a Sterically Encumbered, Oxygen-Deficient Polyoxovanadate-Alkoxide Cluster
- Creators
- Rachel L. Meyer - University of RochesterPere Miro - University of South DakotaWilliam W. Brennessel - University of RochesterEllen M. Matson - University of Rochester
- Resource Type
- Journal article
- Publication Details
- Inorganic chemistry, Vol.60(18), pp.13833-13843
- Publisher
- Amer Chemical Soc
- DOI
- 10.1021/acs.inorgchem.1c00887
- PMID
- 34161731
- ISSN
- 0020-1669
- eISSN
- 1520-510X
- Number of pages
- 11
- Grant note
- CHE-1653195 / National Science Foundation; National Science Foundation (NSF) Cottrell Award from Research Corporation for Science Advancement
- Language
- English
- Date published
- 09/20/2021
- Academic Unit
- Chemistry
- Record Identifier
- 9984618523102771
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