Synthesis, characterization and crystal structure of a novel vanadium-substituted polyoxometalate based on the [BiW9O33]9− units

The new tungstobismutate K2Na6(NH4)6[(VO)2(BiW9O33)2] · 41H2O (1) anion has been obtained by reaction of Na2WO4 · 2H2O, Bi2(SO4)3, and VOSO4 · 5H2O in NaAc buffer under moderate condition, and characterized by IR, UV, element analysis, TG and single-crystal X-ray analysis. Polyoxoanion 1 was composed of two [BiW9O33]9− units linked by two vavadium ions. Compound 1 represents the first dimeric species sandwiching two vanadium metal ions between two lacunary Keggin anions. The crystal data for two compounds are the following: 1, triclinic, space group P−1, a = 12.852(3) Å, b = 16.275(3) Å, c = 24.646(5) Å, α = 70.80(3)°, β = 86.88(3)°, γ = 83.48(3)°, V = 4836.0(17) Å, Z = 2.