Acta Crystallographica Section E: Crystallographic Communications (Feb 2017)

Crystal structure of dicesium hydrogen citrate from laboratory single-crystal and powder X-ray diffraction data and DFT comparison

  • Alagappa Rammohan,
  • Amy A. Sarjeant,
  • James A. Kaduk

DOI
https://doi.org/10.1107/S2056989017000792
Journal volume & issue
Vol. 73, no. 2
pp. 231 – 234

Abstract

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The crystal structure of dicesium hydrogen citrate, 2Cs+·C6H6O72−, has been solved using laboratory X-ray single-crystal diffraction data, refined using laboratory powder X-ray data, and optimized using density functional techniques. The Cs+ cation is nine-coordinate, with a bond-valence sum of 0.92 valence units. The CsO9 coordination polyhedra share edges and corners to form a three-dimensional framework. The citrate anion is located on a mirror plane. Its central hydroxy/carboxylate O—H...O hydrogen bond is short, and (unusually) intermolecular. The centrosymmetric end-end carboxylate hydrogen bond is exceptionally short (O...O = 2.416 Å) and strong. These hydrogen bonds contribute 16.5 and 21.7 kcal mol−1, respectively, to the crystal energy. The hydrophobic methylene groups occupy pockets in the framework.

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