Polyoxometal cations within polyoxometalate anions. Seven-coordinate uranium and zirconium heteroatom groups in [(UO2)12(μ3-O)4(μ2-H2O)12(P2W15O56)4]32− and [Zr4(μ3-O)2(μ2-OH)2(H2O)4 (P2W16O59)2]14−
2003; Elsevier BV; Volume: 656; Issue: 1-3 Linguagem: Inglês
10.1016/s0022-2860(03)00272-2
ISSN1872-8014
AutoresAndrew J. Gaunt, Iain May, David Collison, K.T. Holman, Michael T. Pope,
Tópico(s)Radioactive element chemistry and processing
ResumoTwo new composite polyoxotungstate anions with unprecedented structural features, [(UO2)12(μ3-O)4(μ2-H2O)12(P2W15O56)4]32− (1) and [Zr4(μ3-O)2(μ2-OH)2(H2O)4 (P2W16O59)2]14− (2) contain polyoxo-uranium and -zirconium clusters as bridging units. The anions are synthesized by reaction of Na12[P2W15O56] with solutions of UO2(NO3)2 and ZrCl4. The structure of 1 in the sodium salt contains four [P2W15O56]12− anions assembled into an overall tetrahedral cluster by means of trigonal bridging groups formed by three equatorial-edge-shared UO7 pentagonal bipyramids. The structure of anion 2 consists of a centrosymmetric assembly of two [P2W16O59]12− anions linked by a {Zr4O2(OH)2(H2O)4}10+ cluster. Both complexes in solution yield the expected two-line 31P-NMR spectra with chemical shifts of −2.95, −13.58 and −6.45, −13.69 ppm, respectively.
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