Synthesis, Characterization, and Crystal Structures of Double-Cubane-Substituted and Asymmetric Penta-Ni-Substituted Dimeric Polyoxometalates
2007; American Chemical Society; Volume: 7; Issue: 7 Linguagem: Inglês
10.1021/cg060868m
ISSN1528-7505
AutoresZhiming Zhang, Enbo Wang, Yanfei Qi, Yangguang Li, Baodong Mao, Zhong‐Min Su,
Tópico(s)Vanadium and Halogenation Chemistry
ResumoTwo novel multi-Ni-substituted polyoxometalates K12[(SiW8O31)2Ni7(H2O)4(OH)6]·23H2O (1) and K6Na18[H2{Ni5(H2O)5(OH)3(x-SiW9O34)(β-SiW8O31)}2]·39H2O (2) have been successfully synthesized by routine synthetic reactions in aqueous solution. Single-crystal X-ray analysis was carried out on the two compounds (1 and 2), which both crystallize in the triclinic system. For 1, space group P1̄, a = 11.442(2) Å, b = 11.905(2) Å, c = 17.169(3) Å, α = 107.62(3)°, β = 91.67(3)°, γ = 102.37(3)°, V = 2166.1(8) Å3, Z = 1. For 2, space group P1̄, a = 18.435(4) Å, b = 25.095(5) Å, c = 25.095(5) Å, α = 81.44(3)°, β = 73.87(3)°, γ = 85.31(3)°, V = 9624(3) Å3, Z = 2. Compound 1 represents the first example of the double-cubane Ni7O8-cluster-substituted polyoxometalates, and the [β-SiW8O31] unit in 1 was scarcely reported previously. Compound 2 exhibits a novel asymmetric dimeric structure, consisting of [β-Ni3SiW9O37(H2O)3] and [γ-SiW8Ni2O34(H2O)2] units linked by three μ3-OH groups. In the [β-Ni3SiW9O37(H2O)3] half unit, this fashion of the tri-Ni-substituted was scarcely reported, and in the [γ-SiW8Ni2O34(H2O)2] units, the mode of the di-Ni-substituted is also observed scarcely in the polyoxometalates chemistry.
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