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The tetragonal polymorph of 5,5-dichlorobarbituric acid (m.p. 478 K), C4H2Cl2N2O3, forms an N—H
O hydrogen-bonded tape structure along [001]. Two tapes related by a twofold rotation axis are associated via ClO contacts [3.201 (1) Å], and four such chain pairs are arranged around a fourfold roto-inversion axis. The crystal structures of the monoclinic and orthorhombic polymorphs have been reported previously [Gelbrich et al. (2011). CrystEngComm, 13, 5502–5509].
O hydrogen-bonded tape structure along [001]. Two tapes related by a twofold rotation axis are associated via ClO contacts [3.201 (1) Å], and four such chain pairs are arranged around a fourfold roto-inversion axis. The crystal structures of the monoclinic and orthorhombic polymorphs have been reported previously [Gelbrich et al. (2011). CrystEngComm, 13, 5502–5509].organic compoundsOpen access
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In the title molecular salt [systematic name: (5α,6α)-7,8-didehydro-4,5-epoxy-17-methylmorphinan-3,6-diol hydrochloride], C17H20NO3+·Cl−, the conformation of the morphinium ion is in agreement with the characteristics of the previously reported morphine forms [for example, Gylbert (1973). Acta Cryst. B29, 1630–1635]. In the crystal, the cations and chloride anions are linked into a helical chain propagating parallel to the b-axis direction by N—HCl and O—HCl hydrogen bonds. The title salt and the morphine monohydrate [Bye (1976) Acta Chem. Scand. 30, 549–554] display very similar one-dimensional packing modes of their morphine components.
Cl and O—HCl hydrogen bonds. The title salt and the morphine monohydrate [Bye (1976) Acta Chem. Scand. 30, 549–554] display very similar one-dimensional packing modes of their morphine components.
