Novel copper-complex-substituted tungstogermanates

Two copper-complex-substituted tungstogermanates [Cu-5(2,2'-bpy)(6)(H2O)][GeW8O31]center dot 9H(2)O, 1, and {[Cu-5(2,2'-bpy)(5)(H2O)][GeW9O34]}(2)center dot 7H(2)O, 2 (2,2'-bpy = 2,2'-bipyridyl), have been hydrothermally synthesized and structurally characterized. X-ray structural analyses show that 1 is a rare tetralacunary Keggin anion of [B-beta-GeW8O31](10-) substituted by copper complexes, while dimer 2 consists of two trilacunary [B-alpha-GeW9O34](10-) Keggin units bridged by copper complexes. Magnetic measurement for 2 shows the presence of antiferromagnetic interactions within the dinuclear Cu2+ cations.