Solid-state transformation of 4, 2'-anhydro-5-(beta-D-arabinofuranosyl)uracil dihydrate to 4, 2'-anhydro-5-(beta-D-arabinofuranosyl)uracil monohydrate

Acta Crystallogr C. 2000 Sep:56 ( Pt 9):1129-31. doi: 10.1107/s0108270100007794.

Abstract

Crystals of 4,2'-anhydro-5-(beta-D-arabinofuranosyl)uracil, (I), obtained from an aqueous solution, were characterized as the dihydrate, C(9)H(10)N(2)O(5).2H(2)O, (Ia). In air, these crystals slowly transform to the monohydrate, C(9)H(10)N(2)O(5).H(2)O, (Ib), but remain crystalline. The solid-state transformation proceeds with the loss of one water molecule and a rearrangement of hydrogen-bonded layers of molecules. The furanose ring in (I) has an approximate C4'-exo,O4'-endo twist conformation. The central five-membered ring is slightly puckered. The uracil group is planar within experimental uncertainty.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Arabinofuranosyluracil / analogs & derivatives*
  • Arabinofuranosyluracil / chemistry*
  • Crystallography, X-Ray
  • Heterocyclic Compounds, 3-Ring / chemistry*
  • Models, Molecular
  • Molecular Conformation
  • Uracil / analogs & derivatives*
  • Uracil / chemistry

Substances

  • 4,2'-anhydro-5-arabinofuranosyluracil
  • Heterocyclic Compounds, 3-Ring
  • Arabinofuranosyluracil
  • Uracil