Synthesis and structural characterization of a γ-Keggin-type dimeric silicotungstate with a bis(μ-hydroxo) dizirconium core [(γ-SiW10O36)2Zr2(μ-OH)2]10-

A novel dinuclear zirconium sandwich-type silicotungstate cluster Of [(gamma-SiW10O36)(2)Zr-2(mu-OH)(2)](10-) (1) was synthesized by the reaction of a divacant lacunary gamma-Keggin silicotungstate [gamma-SiW10O36](8-) with ZrOCl2 center dot 8H(2)O. The anion consisted Of two [gamma-SiW10O36](8-) units sandwiching a diamond Zr-2(mu-OH)(2) core, and each zirconium atom in 1 was six-coordinated to two mu-0H ligands and four oxygen atoms Of two [gamma-SiW10O36](8-) units. The Zr-2(mu-OH)(2) core in 1 reacted with methanol to give the corresponding monomethoxo derivative [(gamma-SiW10O36)(2)Zr-2(mu-OH)(mu-OCH3)](10-) (2).