title: Reusable oxidation catalysis using metal-monocatecholato species in a robust metal-organic framework.
abstract: An isolated metal-monocatecholato moiety has been achieved in a highly robust metal-organic framework (MOF) by two fundamentally different postsynthetic strategies: postsynthetic deprotection (PSD) and postsynthetic exchange (PSE). Compared with PSD, PSE proved to be a more facile and efficient functionalization approach to access MOFs that could not be directly synthesized under solvothermal conditions. Metalation of the catechol functionality residing in the MOFs resulted in unprecedented Fe-monocatecholato and Cr-monocatecholato species, which were characterized by X-ray absorption spectroscopy, X-band electron paramagnetic resonance spectroscopy, and (57)Fe Mössbauer spectroscopy. The resulting materials are among the first examples of Zr(IV)-based UiO MOFs (UiO = University of Oslo) with coordinatively unsaturated active metal centers. Importantly, the Cr-metalated MOFs are active and efficient catalysts for the oxidation of alcohols to ketones using a wide range of substrates. Catalysis could be achieved with very low metal loadings (0.5-1 mol %). Unlike zeolite-supported, Cr-exchange oxidation catalysts, the MOF-based catalysts reported here are completely recyclable and reusable, which may make them attractive catalysts for 'green' chemistry processes.
authors.affiliation: Department of Chemistry and Biochemistry and ‡Department of NanoEngineering, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Honghan
authors.initials: H
authors.lastname: Fei
authors.forename: JaeWook
authors.initials: J
authors.lastname: Shin
authors.forename: Ying Shirley
authors.initials: YS
authors.lastname: Meng
authors.forename: Mario
authors.initials: M
authors.lastname: Adelhardt
authors.forename: Jörg
authors.initials: J
authors.lastname: Sutter
authors.forename: Karsten
authors.initials: K
authors.lastname: Meyer
authors.forename: Seth M
authors.initials: SM
authors.lastname: Cohen
mesh_terms: D002384:Catalysis; D002396:Catechols / Q000737:chemistry*; D055772:Green Chemistry Technology; D008670:Metals / Q000737:chemistry*; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D056928:X-Ray Absorption Spectroscopy
chemical_list: D002396:Catechols; D008670:Metals; D009942:Organometallic Compounds