Crystal structure of a second triclinic polymorph of 2-methyl-pyridinium picrate.

The title mol-ecular salt, C6H8N(+)·C6H2N3O7 (-) (systematic name: 2-methyl-pyridinium 2,4,6-tri-nitro-phenolate), crystallizes with two cations and two anions in the asymmetric unit. In the crystal, the cations are linked to the anions via bifurcated N-H⋯(O,O) hydrogen bonds, generating R 1 (2)(6) graph-set motifs. Numerous C-H⋯O hydrogen bonds are observed between these cation-anion pairs, which result in a three-dimensional network.

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

The title mol-ecular salt, C6H8N(+)·C6H2N3O7 (-) (systematic name: 3-methyl-pyridinium 2,4,6-tri-nitro-phenolate), crystallizes in the triclinic space group P-1. The crystal structure of the monoclinic polymorph (space group P21/n) has been reported [Stilinovic & Kaitner (2011 ▸). Cryst.

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.

The title mol-ecular salt, C5H12NO(+)·C12H8N5O9 (-) [common name: 4-methyl-morpholin-4-ium 1,3-dimethyl-5-(2,4,6-tri-nitro-phen-yl)barbiturate], possesses noticeable anti-convulsant and hypnotic activity. In the anion, the 1,3-di-methyl-barbituric acid ring and the symmetrically substituted tri-nitro-phenyl ring, linked via a C-C bond, are not coplanar but subtend an angle of 44.88 (7)°.