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

The title mol-ecular salt, C5H7N2 (+)·C12H8ClN4O7 (-)·0.5H2O, crystallizes as a hemihydrate. The two rings in the barbiturate anion are not coplanar but make a dihedral angle of 43.

2-Amino-pyridinium 5-(5-chloro-2,4-dinitro-phen-yl)-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetra-hydro-pyrimidin-6-olate.

In the title mol-ecular salt, C(5)H(7)N(2) (+)·C(12)H(8)ClN(4)O(7) (-), the dihedral angle between the aromatic rings of the anion is 51.88 (6)°. One of the nitro groups is disordered over two orientations in a 0.

Triethyl-ammonium [2-eth-oxy-carbonyl-2-(2-methyl-benz-yl)-6,9-dinitro-3-oxo-bicyclo-[3.3.1]non-6-en-8-yl-idene]azinate.

In the title salt, C(6)H(16)N(+)·C(20)H(20)N(3)O(9) (-), the cations and anions are connected by N-H⋯O hydrogen bonds. The structure is consolidated by weak C-H⋯O inter-actions.