Doraisamyraja Kalaivani

Triethyl­ammonium 2,4-dinitro­phenyl­barbiturate

In the title molecular salt [systematic name: triethylammonium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate], C6H16N+·C10H5N4O7 −, the cation and anion are linked by an N—H⋯O hydrogen bond. In the crystal, inversion-related barbiturate rings are centrosymmetrically connected through pairs of N—H⋯O hydrogen bonds, forming R 2 2(8)R 2 2(8) ring motifs.

N,N-Diethyl-2-hy-droxy-ethanaminium 2,6-dioxo-5-(2,4,6-trinitro-phen-yl)-1,2,3,6-tetra-hydro-pyrimidin-4-olate dihydrate.

In the title molecular salt, C6H16NO+·C10H4N5O9 −·2H2O, which crystallizes as a dihydrate, O—H⋯O hydrogen bonds link the barbiturate anion, the ethanaminium cation and the water molecules of crystallization. The dihedral angle between the rings in the anion is 43.71 (8)°. In the crystal, an R 2 2(8) ring motif hydrogen-bonding pattern is also found involving inversion-related barbiturate rings with N—H⋯O hydrogen bonds. As a result of the various hydrogen bonds an infinite two-dimensional network, propagating in (10), is formed.

2-Methyl-pyridinium 5-(2,4-dinitro-phen-yl)-1,3-dimethyl-barbiturate.

In the title molecular salt [systematic name: 2-methylpyridinium 5-(2,4-dinitrophenyl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate], C6H8N+·C12H9N4O7 −, the cation and anion are linked a through strong N—H⋯O hydrogen bond. In the crystal, C—H⋯O interactions link the ions, generating a chain along [010].

N,N-Diethyl-2-hy-droxy-ethanaminium 5-(5-chloro-2,4-dinitro-phen-yl)-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-4-olate hemihydrate.

The asymmetric unit of the title salt, C6H16NO+·C10H4ClN4O7 −·0.5H2O, contains two cations, two anions and one water molecule. In one independent anion, one nitro group is rotationally disordered over two orientations in a 0.657 (8):0.343 (8) ratio. In the crystal, intermolecular N—H⋯O and O—H⋯O hydrogen bonds link all the components into ribbons extending along [100].

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 R 2 2(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.

2-Amino­pyridinium 5-(5-chloro-2,4-dinitro­phen­yl)-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidin-6-olate

In the title molecular salt, C5H7N2 +·C12H8ClN4O7 −, 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 0.710 (6):0.290 (6) ratio. In the crystal, the cations and anions are linked by N—H⋯O hydrogen bonds, generating infinite ribbons extending along [100] which incorporate R 4 4(22) ring motifs. Weak C—H⋯O interactions also occur.

Triethyl­ammonium 1,3-dimethyl-5-(2,4,6-trinitro­phenyl)barbiturate

In the title molecular salt [systematic name: triethylammonium 1,3-dimethyl-2,6-dioxo-5-(2,4,6-trinitrophenyl)-1,2,3,6-tetrahydropyrimidin-4-olate], C6H16N+·C12H8N5O9 −, 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 substantially 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 supramolecular chains extending in the [001] direction.

Crystal structure and biological evaluation of 4-methyl-morpholin-4-ium 1,3-dimethyl-2,6-dioxo-5-(2,4,6-tri-nitro-phen-yl)-1,2,3,6-tetra-hydro-pyrimidin-4-olate.

In the crystal of title molecular salt, the protonated N atom of the 4-methylmorpholin-4-ium cation forms a hydrogen bond with a carbonyl O atom of the barbiturate anion. This N—H⋯O hydrogen bond contributes to the good stability of the reported salt, which exhibits noticeable anticonvulsant and hypnotic activity.

Crystal structure of 3-methyl-pyridinium picrate: a triclinic polymorph.

In the crystal of the title molecular salt, the 3-methylpyridinium cation and the picrate anion are linked via bifurcated N—H⋯(O,O) hydrogen bonds, forming an (6) ring motif. These units are linked via C—H⋯O hydrogen bonds, forming a three-dimensional framework·The compound exhibits anticonvulsant activity.

N,N-Diethyl­anilinium 5-(5-chloro-2,4-dinitro­phen­yl)-2,6-dioxo-1,2,3,6-tetra­hydro­pyrimidin-4-olate

In the anion of the title salt, C10H16N+·C10H4ClN4O7 − [trivial name = N,N-diethylanilinium 5-(3-chloro-4,6,-dinitrophenyl)barbiturate], the dihedral angle between the benzene and pyrimidine rings is 45.49 (6)°. The mean plane of the nitro group, which is ortho-substituted with respect to the pyrimidine ring, is twisted by 41.57 (13)° from the benzene ring, while the mean plane of the nitro group, which is para-substituted, is twisted by 14.41 (12)° from this ring. In the crystal, N—H⋯O hydrogen bonds link cations and anions into chains along [1-10]. Within the chains, inversion-related anionic barbiturate anions form R 2 2(8) ring motifs.