Publication

Journal	Zeitschrift fur Anorganische und Allgemeine Chemie
Volume (Issue)	640(5)
Page(s)	781 - 789
Title of proceedings	Zeitschrift fur Anorganische und Allgemeine Chemie
DOI	10.1002/zaac.201300669

A series of new gallium-containing silicotungstates was obtained from the one step reaction of the lacunary Na10[α-SiW9O 34]·15H2O Keggin-type building block (SiW 9) with gallium nitrate in aqueous solution. The sandwich-type polyoxotungstate [Ga6(H2O)x{α-SiW 9O34(OH)y}2]n- (1) crystallizes first as a mixture of two similar polyoxometalates (1a and 1b), while [Ga4(H2O)2{α-SiW10O 38}2]12- (2) is generated from the mother liquor in a second step. Both newly obtained polyoxometalates with tetra- and hexanuclear gallium cores were structurally characterized with a wide range of methods encompassing single crystal and powder X-ray diffraction techniques, FT-IR spectroscopy, and thermal analysis. The solution stability of both dimeric POMs K10[Ga6(H2O)3{α-SiW 9O35(OH)2}2]·35.5H 2O (1a) and K12[Ga4(H2O) 2{α-SiW10O38}2] ·30H2O (2) was investigated with 183W NMR and HR ESI mass spectrometry, and the electrochemical properties of both compounds were determined by cyclic voltammetry. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.