Synthesis and characterization of two new polyoxomolybdate compounds:: [Cu(imi)2(H2O)4][Himi]2[(imi)2Mo8O26] and [Himi]3[H3O][SiMo12O40] • H2O

Two new compounds, [CU(imi)(2)(H2O)(4)][Himi](2)[(imi)(2)Mo8O26] (1) and [Himi](3)[H3O][SiMo12O40].H2O (2) (imi = imidazole), have been synthesized and characterized by single crystal X-ray analysis, IR spectra and elemental analysis. Compound 1 consists of an imidazole-coordinated octamolybdate anion, two protonated imidazole cations and one imidazole and water coordinating copper cation per unit cell. Compound 2 is built up of the Keggin-type [SiMo12O40](4-) anions, protonated imidazole cations, hydroxonium ions and lattice water molecules. Both compounds 1 and 2 are three-dimensional frameworks held together by complex hydrogen bonding. (C) 2003 Elsevier Ltd. All rights reserved.