Polyoxometalate

About: Polyoxometalate is a research topic. Over the lifetime, 3493 publications have been published within this topic receiving 94123 citations. The topic is also known as: POM.

Efficient Mechanochemical Synthesis of Polyoxometalate⊂ZIF Complexes as Reusable Catalysts for Highly Selective Oxidation

Abstract: One-pot mechanochemical synthesis was demonstrated to be an efficient strategy to synthesize host–guest POM⊂rho-ZIF complexes (POM = polyoxometalate; rho-ZIF = zeolitic imidazolate framework with rho topology) with high crystallinity. In this work, the metastable rho-ZIF with large interior cavities and windows was used as host matrix for encapsulating and immobilizing bulky guest molecules with high loading efficiency and chemical stability. As novel catalysts, POM⊂rho-ZIF complexes were found effective for the selective oxidation of a series of sulfides to sulfoxides. Moreover, the heterogeneity of these composite catalysts was confirmed by leaching tests, and they can be recycled at least four times without significant loss of activity.

Synthesis and characterization of 2D and 3D structures from organic derivatives of polyoxometalate clusters: role of organic moiety, counterion, and solvent.

Abstract: New organic derivatives of “inverse-Keggin” polyoxometalate (POM) clusters, [Mo12O46(AsR)4]4- (R = C6H4-4-COOH, C6H3-4-OH-3-NO2, C6H4-4-OH), have been synthesized. Structures of the corresponding sodium or iron salts were elucidated by single-crystal X-ray diffraction and shown to be 3D structures connected through hydrogen bonds and/or O−Na−O linkages. Parameters which influence the final solid-state architecture, such as the crystallizing solvent, organic moiety, and counterions, have been examined. The hydrogen-bonding ability of the solvent affects the connectivity of the POM clusters through interactions with the organic group and the inorganic core. The organic groups influence the structure through hydrogen bonds to other organic groups, to neighboring clusters, and/or to solvent molecules. Hydrogen bonding between the organic groups and the solvent appears to inhibit some possible connectivity patterns, such as the hydrogen-bonded dimerization of carboxylic acid groups. Na+ ions were found directl...

Palladium(II)/Polyoxometalate-Catalyzed Direct C-3 Alkenylation of Indoles using Dioxygen as the Terminal Oxidant

Abstract: An efficient and practical synthetic method has been developed for the preparation of 3-vinylindoles by the direct CH olefination of indoles with alkenes. The transformation is catalyzed by palladium acetate combined with 12-molybdophosphoric acid and uses oxygen as the terminal oxidant. 4-Dimethylaminopyridine (DMAP) was observed to be an effective additive for the olefination reaction. Functional groups such as methoxy, benzyloxy, fluoro, bromo, ester, phenyl, and methyl were tolerated under the reaction conditions.