A γ-Keggin-type dimeric silicotungstate sandwiching an adamantanoid tetra-nuclear ruthenium-oxygen cluster core

A novel ruthenium-containing silicotungstate of [(CH3)(2)NH2](8)K2H2[(gamma-SiW10O36)(2)Ru4Cl4O2(OH)(4)]center dot 23H(2)O (1) was obtained as a single crystal suitable for X-ray crystallographic analysis by the reaction of a divacant lacunary gamma-Keggin silicotungstate K-8[gamma-SiW10O36] with K-2[RuCl5(OH2)]. The unprecedented dimeric silicotungstate consisted of two [gamma-SiW10O36](8-) units sandwiching an adamantanoid ruthenium-oxygen cluster core [Ru4Cl4O2(OH)(4)](4+).