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)]center dot 4H(2)O (1) anion has been obtained by reaction of Na2WO4 center dot 2H(2)O, Bi-2(SO4)(3), and VOSO4 center dot 5H(2)O 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 I 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) angstrom, b = 16.275(3) angstrom, c = 24.646(5) A, a = 70.80(3)degrees, = 86.88(3)degrees, gamma = 83.48(3)degrees, V= 4836.0(17) angstrom, Z = 2. (c) 2007 Elsevier B.V. All rights reserved.