Trimethylammonium 2,6-dioxo-5-(2,4,6-trinitrophenyl)-1,2,3,6-tetrahydropyrimidin-4-olate

In the title barbiturate salt (trivial name: trimethylammonium 2,4,6-trinitrophenylbarbiturate), C3H10N+·C10H4N5O9−, the asymmetric unit contains two sets of anion–cation moieties. The dihedral angle between the rings in the anions are 44.0 (3) and 45.7 (3)°. Adjacent anions are connected into ribbons along [100] through R22(8) ring motifs formed by N—H...O hydrogen bonds involving the barbiturate rings. Attached to both sides of these ribbons via N—H...O hydrogen bonds are the trimethylammonium cations. C—H...O hydrogen bonds are also observed.