title: Violuric acid monohydrate: a second polymorph with more extensive hydrogen bonding.
abstract: Crystals of a second polymorph of violuric acid monohydrate [systematic name: pyrimidine-2,4,5,6(1H,3H)-tetrone monohydrate], C(4)H(3)N(3)O(4).H(2)O, have higher density and a more extensive hydrogen-bonding arrangement than the previously reported polymorph. Violuric acid and water molecules form essentially planar hydrogen-bonded sheets, which are stacked in an offset ...ABCABC... repeat pattern involving no ring-stacking interactions.
authors.affiliation: School of Natural Sciences (Chemistry), Newcastle University, Newcastle upon Tyne, England.
authors.forename: Kathy
authors.initials: K
authors.lastname: Guille
authors.forename: Ross W
authors.initials: RW
authors.lastname: Harrington
authors.forename: William
authors.initials: W
authors.lastname: Clegg
mesh_terms: D001463:Barbiturates / Q000737:chemistry*; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D007536:Isomerism; D008968:Molecular Conformation
chemical_list: D001463:Barbiturates; C094277:violuric acid