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In chemistry a tungstate is a compound that contains an oxoanion of tungsten or is a mixed oxide containing tungsten. The simplest tungstate ion is WO42−, "orthotungstate".〔Egon Wiberg, Arnold Frederick Holleman (2001) ''Inorganic Chemistry'', Elsevier ISBN 0-12-352651-5〕 Many other tungstates belong to a large group of polyatomic ions that are termed polyoxometalates, ("POMs"), and specifically termed isopolyoxometalates as they contain, along with oxygen and maybe hydrogen, only one other element. Almost all useful tungsten ores are tungstates.〔Erik Lassner, Wolf-Dieter Schubert, Eberhard Lüderitz, Hans Uwe Wolf "Tungsten, Tungsten Alloys, and Tungsten Compounds" in Ullmann's Encyclopedia of Industrial Chemistry 2000, Wiley-VCH, Weinheim. 〕 ==Structures== Orthotungstates feature tetrahedral W(VI) centres with short W-O distances of 1.79 Å. Structurally, they resemble sulfates. Six-coordinate, octahedral tungsten dominates in the polyoxotungstates. In these compounds, the W-O distances are elongated.〔 Some examples of tungstate ions: * HWO4− (hydrogentungstate)〔 * polymeric W2O72− ions of various structures in Na2W2O7, Li2W2O7 and Ag2W2O7〔Wells A.F. (1984) ''Structural Inorganic Chemistry'' 5th edition Oxford Science Publications ISBN 0-19-855370-6〕 * ()6− (paratungstate A)〔 * ()4− (tungstate Y)〔Jon A. McCleverty, N. G. Connelly,Nomenclature of inorganic chemistry II: recommendations 2000, International Union of Pure and Applied Chemistry Commission on the Nomenclature of Inorganic Chemistry, Published by Royal Society of Chemistry, 2001, ISBN 0-85404-487-6〕 * ()10− (paratungstate B) 〔 * α-()6− (metatungstate)〔) * β-()6− (tungstate X)〔) See the for a list of tungstates. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Tungstate」の詳細全文を読む スポンサード リンク
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