The First Sandwich‐Type Heteropolytungstates Consisting of Trivacant Gallium( III )‐Substituted Keggin Fragments

The new polyoxotungstates (NH 4 ) 5 Na 9 [Cu 4 (H 2 O) 2 (GaW 9 O 34 ) 2 ] · 22 H 2 O ( 1 ) and (NH 4 ) 14 [Zn 4 (H 2 O) 2 (GaW 9 O 34 ) 2 ] · 37 H 2 O ( 2 ) were synthesized in aqueous solution and characterized by IR and Raman spectroscopy, energy dispersive X‐ray fluorescence and single‐crystal X‐ray analysis. Compounds 1 and 2 contain the trivacant α‐B‐(GaW 9 O 34 ) 11– Keggin fragment, which is structurally characterized for the first time. The lacunary (GaW 9 O 34 ) 11– structure exhibits a centered Ga III atom, which is bound to four oxygen atoms and thus achieves a tetrahedral coordination sphere. The synthesis of 1 – 2 enlarges the class of sandwich‐type polyoxoanions and enables the syntheses of a new series of gallium( III )‐substituted polyoxotungstates. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)