Acta Crystallographica Section C

Crystal Structure Communications

Volume 59, Part 4 (April 2003)

metal-organic compounds

Acta Cryst. (2003). C59, m152-m155 [ doi:10.1107/S0108270103004517 ]

Synchrotron structure determination of an -Keggin doubly Pt^IV-substituted silicotungstate, (CH₆N₃)₈[-SiPt₂W₁₀O₄₀]·6H₂O

U. Lee, H.-C. Joo, K.-M. Park and T. Ozeki

Abstract: The crystal structure of octaguanidinium [alpha] -silicodiplatinodecatungstate hexahydrate, (CH₆N₃)₈[ [alpha] -SiPt₂W₁₀O₄₀]·6H₂O, has been analyzed via a high-energy X-ray diffraction experiment at the SPring-8 BL04B2 beamline. The title compound contains a novel [alpha] -Keggin heteropolyanion in which two of the addenda atoms are replaced by Pt atoms. W and Pt atoms occupy the same coordinates; the occupancy fractions are ${{5}\over{6}}$ (W) and ${{1}\over{6}}$ (Pt), and the [alpha] -Keggin anion has $\overline 4$ symmetry. The two types of W(Pt)-W(Pt) distance are in the ranges 3.3565 (4)-3.3704 (4) and 3.7033 (4)-3.7100 (4) Å, the four types of W(Pt)-O bond length are in the ranges 1.721 (5)-1.725 (5), 1.910 (5)-1.932 (5), 1.934 (5)-1.956 (5) and 2.339 (4)-2.348 (4) Å, and the Si-O bond length is 1.646 (4) Å.

Formula: (CH₆N₃)₈[Pt₂W₁₀O₄₀Si]·6H₂O