Synthesis and reversible transformation of Cu(n)-bridged (n = 1, 2, or 4) silicodecatungstate dimers.
Three copper-bridged sandwich-type silicodecatungstate dimers, TBA(8)[Cu(γ-SiW(10)O(34))(2)(CH(3)CONH)(2)]·4H(2)O (Cu-1, TBA = tetra-n-butylammonium), TBA(8)H(4)[Cu(2)(γ-SiW(10)O(36))(2)H(2)O]·11H(2)O·CH(3)COCH(3) (Cu-2), and TBA(8)H(2)[Cu(4)(γ-SiW(10)O(36))(2)(CH(3)COO)(2)]·5H(2)O (Cu-4) have been selectively synthesized by reactions of divacant lacunary TBA(4)[H(4)(γ-SiW(10)O(36))] (SiW10) with copper acetate in organic media. The copper cation(s) in Cu-1, Cu-2, and Cu-4 possess square-planar four-coordinate (Cu-1), square-pyramidal five-coordinate (Cu-2), and octahedral six-coordinate (Cu-4) geometries, respectively. These compounds can reversibly be transformed simply by controlling the copper/SiW10 molar ratios in solutions.
Department of Applied Chemistry, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan.
Kosuke
K
Suzuki
Masahiro
M
Shinoe
Noritaka
N
Mizuno