Synthesis and structure of asymmetric zirconium-substituted silicotungstates, [Zr6O2(OH)4(H2O)3(beta-SiW10O37)3]14- and [Zr4O2(OH)2(H2O)4(beta-SiW10O37)2]10-.
The reaction of ZrCl4 with [gamma-SiW10O36]8- in a potassium acetate buffer results in two different products depending on the reactant ratios. The trimeric species [Zr6O2(OH)4(H2O)3(beta-SiW10O37)3]14- (1) consists of three beta23-SiW10O37 units linked by an unprecedented Zr6O2(OH)4(H2O)3 cluster with C1 point group symmetry. The dimeric species [Zr4O2(OH)2(H2O)4(beta-SiW10O37)2]10- (2) consists of beta22- and beta12-SiW10O37 units sandwiching a Zr4O2(OH)2(H2O)4 cluster, which also has C1 symmetry. Polyanion 1 contains more zirconium centers than any other polyoxometalate known to date.
Bassil
Bassem S
BS
School of Engineering and Science, International University Bremen, P.O. Box 750561, 28725 Bremen, Germany.
Dickman
Michael H
MH
Kortz
Ulrich
U