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 [(γ-SiW10O36)2Zr2(μ-OH)2]10- (1) was synthesized by the reaction of a divacant lacunary γ-Keggin silicotungstate [γ-SiW10O36]8- with ZrOCl2·8H2O. The anion consisted of two [γ-SiW10O36]8- units sandwiching a diamond Zr2(μ-OH)2 core, and each zirconium atom in 1 was six-coordinated to two μ-OH ligands and four oxygen atoms of two [γ-SiW10O36]8- units. The Zr2(μ-OH)2 core in 1 reacted with methanol to give the corresponding monomethoxo derivative [(γ-SiW10O36)2Zr2(μ-OH)(μ-OCH3)]10- (2).