6-Methyluracil: a redetermination of polymorph (II)
6-Mehyluracil, C5H6N2O2, exists in two crystalline phases: form (I), monoclinic,
space group P21/c [Reck et al. (1988). Acta Cryst. A44, 417–421]. and form (II),
monoclinic, space group C2/c [Leonidov et al. (1993). Russ. J. Phys. Chem. 67,
2220–2223]. The structure of polymorph (II) has been redetermined providing a
significant increase in the precision of the derived geometric parameters. In the
crystal, molecules form ribbons approximately running parallel to the c-axis
direction through N—H O hydrogen bonds. The radical differences observed