4-Chloro-1H-pyrrolo-[2,3-d]pyrimidine.

The title compound, C(6)H(4)ClN(3), is essentially planar with the pyrrole and pyrimidine rings inclined to one another by 0.79 (15)°. In the crystal, mol-ecules are connected via pairs of N-H⋯N hydrogen bonds, forming inversion dimers. These dimers are linked via C-H⋯N inter-actions, forming a two-dimensional network parallel to (10-1).

3-Methyl-4-nitro-phenol.

In the title mol-ecule, C(7)H(7)NO(3), the nitro group is oriented at 14.4 (3)° with respect to the plane of the benzene ring. The crystal structure is stabilized by O-H⋯O hydrogen bonds and further consolidated by C-H⋯O inter-actions.

2-Chloro-6-methyl-pyrimidin-4-amine.

In the crystal structure of the title compound, C5H6ClN3, mol-ecules are linked by pairs of N-H⋯N hydrogen bonds, forming inversion dimers. These dimers are linked via N-H⋯N hydrogen bonds, forming a two-dimensional network lying parallel to (100). Inversion-related mol-ecules are also linked via a slipped π-π inter-action, with a centroid-centroid distance of 3.5259 (11) Å, a normal separation of 3.4365 (7) Šand a slippage of 0.789 Å.

Methyl 1-(2,6-difluoro-benz-yl)-1H-1,2,3-triazole-4-carboxyl-ate.

In the title compound, C(11)H(9)F(2)N(3)O(2), the triazole ring is planar, with an r.m.s. deviation of 0.0048 Å, and makes a dihedral angle of 77.3 (1)° with the benzene ring. In the crystal, weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds link the mol-ecules into chains along the b axis.

(Z)-3-(Benzyl-carbamo-yl)prop-2-enoic acid.

The title compound, C(11)H(11)NO(3), was synthesized by the reaction of maleic andydride and phenyl-methanamine. The mol-ecular conformation is stabilized by by an intra-molecular O-H⋯O hydrogen bond. In the crystal, mol-ecules are linked by inter-molecular N-H⋯O and C-H⋯O hydrogen bonds, forming a chain along the b axis.

2-(4-Bromo-phen-yl)-1-ethyl-1H-1,3-benzodiazole.

In the title compound, C(15)H(13)BrN(2), the benzimidazole group is almost planar, as indicated by the dihedral angle of 2.6 (3)° between the best planes through the benzene and imidazole rings. The best plane through the attached benzene makes an angle of 44.5 (2)° with the best plane through the benzimidazole system. C-H⋯π inter-actions are observed in the crystal structure.

3,3'-Dimethyl-1,1'-(propane-1,3-di-yl)diimidazol-1-ium bis(hexafluoro-phosphate).

In the title compound, C(11)H(18)N(4) (2+)·2PF(6) (-), the dihedral angle between the two planar imidozlium rings is 6.1 (2)°. Both [PF(6)](-) anions are disordered [occupancies 0.65 (2):0.35 (2) and 0.59 (5):0.41 (5)]. The crystal packing is stabilized by inter-molecular C-H⋯F hydrogen bonds which link two mol-ecules, forming centrosymmetric dimers.

N,N'-Di-p-tolyl-ethyl-enediamine.

The asymmetric unit of the title compound, C(16)H(20)N(2), contains two independent mol-ecules. The rings in each mol-ecule are oriented at dihedral angles of 78.94 (3) and 77.76 (3)°.