Triethyl-ammonium 1,3-dimethyl-5-(2,4,6-trinitro-phenyl)barbiturate.

In the title mol-ecular salt [systematic name: triethyl-ammonium 1,3-dimethyl-2,6-dioxo-5-(2,4,6-trinitro-phen-yl)-1,2,3,6-tetra-hydro-pyrimidin-4-olate], C(6)H(16)N(+)·C(12)H(8)N(5)O(9) (-), the dihedral angle between the aromatic rings in the anion is 46.88 (8)°. The nitro group para to the ring junction is almost coplanar with its attached ring [dihedral angle = 0.76 (3)°], but the two ortho-nitro groups are substanti-ally twisted from the ring plane, by 47.91 (2) and 42.90 (1)°. In the crystal, the cation and anion are linked by an N-H⋯O=C hydrogen bond; these dimeric associations are further connected by weak C-H⋯O bonds to form linear supra-molecular chains extending in the [001] direction.