Crystal structure of 4-amino­pyridinium 5-(5-chloro-2,4-dinitrophenyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate hemihydrate

In the title mol­ecular salt, the two rings of the barbiturate anion are inclined to one another by 43.40 (3)°. In the crystal, the cations and anions are linked via N—H...O hydrogen bonds, forming zigzag chains along [10], which in turn are linked by O—H...O and C—H...O hydrogen bonds, forming slabs lying parallel to (10).

Crystal structure of tri­methyl­ammonium 5-(2,4-di­nitro­phen­yl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetra­hydro­pyrimidin-4-olate

The asymmetric unit of the title mol­ecular salt, C₃H₁₀N⁺·C₁₂H₉N₄O₇⁻ [alternative name: tri­methyl­ammonium 5-(2,4-di­nitro­phen­yl)-1,3-dimethyl barbiturate], contains one anion and two half-occupancy cations. The cations are disordered about inversion centres. The tetra­hydro­pyrimidine ring is essentially planar [maximum deviation = 0.007 (2) Å] and forms a dihedral angle of 41.12 (6)° with the plane of the benzene ring. In the crystal, N—H...O hydrogen bonds link the cations to the anions.