Keggin structureJames F. Keggin, the discoverer of the Keggin Structure.Keggin structure
The Keggin structure is the best known structural form for heteropoly acids. It is the structural form of α-Keggin anions, which have a general formula of [XM12O40]n−, where X is the heteroatom (most commonly are pentavalent phosphorus PV, tetravalent silicon SiIV, or trivalent boron BIII), M is the addendum atom (most common are molybdenum Mo and tungsten W), and O represents oxygen.[1] The structure self-assembles in acidic aqueous solution and is a commonly used type of polyoxometalate catalysts.
^Housecroft, C. E.; Sharpe, A. G. (2004). Inorganic Chemistry (2nd ed.). Prentice Hall. pp. 660–662. ISBN 978-0-13-039913-7.
The Kegginstructure is the best known structural form for heteropoly acids. It is the structural form of α-Keggin anions, which have a general formula...
was characterized by X-ray crystallography 1934. This structure is called the Kegginstructure after its discoverer. The 1970's witnessed the introduction...
recur. The Keggin ion for example is common to both molybdates and tungstates with diverse central heteroatoms. The Keggin and Dawson structures have...
three missing octahedra. As in Kegginstructures, the Dawson structure has an oxyanion at its core. Unlike Kegginstructures, there are two such anions,...
(Pauling) The structure was determined by J.F Keggin first published in 1933 and then in 1934 and is generally known as the Kegginstructure. The anion has...
of the mixture with hydrochloric acid. The polyoxo cluster adopts a Kegginstructure, with Td point group symmetry. Silicotungstic acid is an irritating...
and Laden to show that the material is based on Al13 units with a Keggin ion structure and that this base unit then undergoes complex transformations to...
Retrieved 2018-10-06. Dias, J. A.; Dias, S. C. L.; Caliman, E. (2014). "KegginStructure Polyoxometalates". Inorganic Syntheses: Volume 36. Inorganic Syntheses...
atoms. This results in 3-dimensional structures called polyoxometalates. Typical examples occur in the Kegginstructure of the phosphomolybdate ion. Edge...
silicon and arsenic. The heteropoly-molybdenum blues have structures based on the Kegginstructure. The blue colour arises because the near-colourless anion...
the Keggin anion as the basis of the structural unit. It also recognizes the work of J.F. Keggin who first experimentally described the structure of the...
solid, which adopts a polymeric structure. Molybdenum(V) chloride MoCl5 dark green solid, which adopts a dimeric structure. Molybdenum(VI) chloride MoCl6...
of Dimethyl Carbonate from Methanol and Carbon Dioxide over Co1.5PW12O40 Keggin-Type Heteropolyanion". International Journal of Molecular Sciences. 11 (4):...
aqueous catalytic partial oxidation of wet biomass by the OxFA process. A Keggin-type polyoxometalate (H5PV2Mo10O40) is used as the homogeneous catalyst...
tetrahedral coordination of chromium(III) has been reported for the Cr-centered Keggin anion [α-CrW12O40]5–. Chromium(III) hydroxide (Cr(OH)3) is amphoteric, dissolving...
as a symmetric cluster of twelve tungsten-oxygen octahedra known as the Keggin anion. Many other polyoxometalate anions exist as metastable species. The...
aqueous solution: correlations between the "Core-links" model and "Cage-like" Keggin-Al13 model". Coord. Chem. Rev. 248 (5–6): 441–455. doi:10.1016/j.ccr.2003...
tetrahedral coordination of chromium(III) has been reported for the Cr-centered Keggin anion [α-CrW12O40]5–. Chromium(III) hydroxide (Cr(OH)3) is amphoteric, dissolving...
Ophirite (IMA2013-017) is a mineral with a heteropolytungstate tri-lacunary keggin anion. Melcherite (IMA2015-018) and peterandresenite (IMA2012-084) have...
formation of hydroxide bridges, forming many oligomeric ions, such as the Keggin ion [Al13O4(OH)24(H2O)12]7+. The process ends with precipitation of aluminium...
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