Showing papers by "Shiro Hikichi published in 2006"
TL;DR: In this article, a novel titanium-substituted silicotungstate cluster of [{γ-SiTi2W10O36(OH)2}2(μ-O)2]8- (1) is synthesized by the introduction of titanium(IV) ions into a divacant lacunary γ-Keggin-type polyoxometalate.
Abstract: A novel titanium-substituted silicotungstate cluster of [{γ-SiTi2W10O36(OH)2}2(μ-O)2]8- (1) is synthesized by the introduction of titanium(IV) ions into a divacant lacunary γ-Keggin-type silicotungstate of [γ-SiW10O36]8-. This titanium-substituted polyoxometalate, 1, exhibits a dimeric structure. One half of the γ-Keggin fragment of 1 contains a dinuclear titanium center bridged by two hydroxo groups, and the resulting Ti2(μ-OH)2 core connects to the other Ti2(μ-OH)2 core of the paired γ-Keggin subunit through Ti−O−Ti linkages. The Ti2(μ-OH)2 core of 1 reacts with MeOH to form the corresponding alkoxo derivative, [{γ-SiTi2W10O36(OH)(OMe)}2(μ-O)2]8- (2). Two of four hydroxo groups of the Ti2(μ-OH)2 cores in 1 are replaced by methoxo groups to give the Ti2(μ-OH)(μ-OMe) core, and the Ti−O−Ti linkages connecting two γ-Keggin subunits are maintained in 2. The γ-Keggin dititanium-substituted silicotungstate 1 catalyzes mono-oxygenation reactions, such as the epoxidation of olefins and sulfoxidation of sulfides ...
87 citations
43 citations
TL;DR: A mononuclear side-on peroxo managanese (III) complex, TpiPr2Mn(η2-O2)(imMeH) (3) was prepared by the reaction of [TpiPr 2Mn (O)]2 with excess amount of H2O2 in the presence of 2-methylimidazole (IMMeH), its X-ray structure clearly demonstrated the involvement of intermolecular hydrogen bonding interaction between η 2-peroxide and imidazolyl N-H functional
37 citations
TL;DR: In this article, an efficient H2O2-based oxidation system with three kinds of polyoxometalates, [γ-SiW10O34(H2O)2]4−
32 citations