title: Synthesis and characterization of the platinum-substituted Keggin anion α-H2SiPtW11O40(4-).
abstract: Acidification of an aqueous solution of K8SiW11O39 and K2Pt(OH)6 to pH 4 followed by addition of excess tetramethylammonium (TMA) chloride yielded a solid mixture of TMA salts of H2SiPtW11O40(4-) (1) and SiW12O40(4-) (2). The former was separated from the latter by extraction into an aqueous solution and converted into tetra-n-butylammonium (TBA) and potassium salts TBA-1 and K-1. The α-H2SiPtW11O40(4-) was identified as a monosubstituted Keggin anion using elemental analysis, IR spectroscopy, X-ray crystallography, electrospray ionization mass spectrometry, (195)Pt NMR spectroscopy, (183)W NMR spectroscopy, and (183)W-(183)W 2D INADEQUATE NMR spectroscopy. Both TBA-1 and K-1 readily cocrystallized with their unsubstituted Keggin anion salts, TBA-2 and K-2, respectively, providing an explanation for the historical difficulty of isolating certain platinum-substituted heteropolyanions in pure form.
authors.affiliation: Department of Chemistry, University of California , 419 Latimer Hall, Berkeley, California 94720, United States.
authors.forename: Peter
authors.initials: P
authors.lastname: Klonowski
authors.forename: James C
authors.initials: JC
authors.lastname: Goloboy
authors.forename: Fernando J
authors.initials: FJ
authors.lastname: Uribe-Romo
authors.forename: Furong
authors.initials: F
authors.lastname: Sun
authors.forename: Lingyang
authors.initials: L
authors.lastname: Zhu
authors.forename: Felipe
authors.initials: F
authors.lastname: Gándara
authors.forename: Corinne
authors.initials: C
authors.lastname: Wills
authors.forename: R John
authors.initials: RJ
authors.lastname: Errington
authors.forename: Omar M
authors.initials: OM
authors.lastname: Yaghi
authors.forename: Walter G
authors.initials: WG
authors.lastname: Klemperer