title: Rubidium 2,4,6-trioxo-1,3-diazinan-5-ide-1,3-diazinane-2,4,6-trione-water (1/1/1).
abstract: The asymmetric unit of the title compound, Rb(+)·C(4)H(3)N(2)O(3) (-)·C(4)H(4)N(2)O(3)·H(2)O, consists of one rubidium cation, a barbituric acid mol-ecule, a barbiturate anion and one water mol-ecule. The rubidium ion has seven close-contact inter-actions with O atoms, with Rb⋯O distances ranging from 2.8594 (16) to 3.2641 (14) Å. These seven O atoms together with an eighth O atom at 3.492 (2) Å away from Rb form a distorted polyhedron with shape inter-mediate between an anti-prism and a dodeca-hedron. The Rb(+) ions connect layers built of organic components and water mol-ecules linked via N-H⋯O and O-H⋯O hydrogen bonds.
authors.affiliation: Faculty of Chemistry, Jagiellonian University, Ingardena 3, 30-060 Kraków, Poland.
authors.forename: Marlena
authors.initials: M
authors.lastname: Gryl
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Stadnicka