Abstract
The title compound, C9H8Br2N2O6, crystallizes as hemihydrate in space group P62 with a=12.612 (1), c=13.431 (1) A, and Z=6. The structure was solved by a combination of the direct and the heavy atom methods and refined to an R value of 0.051. The novel structure having two oxygen bridges between the base and the sugar was confirmed by the analysis. The base is oriented anti with respect to the sugar with torsional angles C (6)-N (1)-C (1')-O (1')=57.2°and C (6)-N (1)-C(1')-C(2')=-55.6°, and the sugar ring is in a half-chair form, C(1')-endo-C(2')-exo. The oxygen atom of the water molecule lies on the two-fold axis and three independent hydrogen bonds connect the molecules of nucleoside and water in the crystals.
