1-Meth-oxycarbonyl-2-(4-nitro-phen-yl)ethanaminium nitrate.

In the title compound, C(10)H(13)O(4)N(2) (+)·NO(3) (-), the nitro group and the benzene ring are essentially coplanar. The dihedral angle between the benzene ring and the methyl-carboxyl-ate plane is 49.6 (3)°. The crystal structure is stabilized by cation-anion N-H⋯O and N-H⋯N hydrogen bonds, building sheets parallel to (001).

(1S,2S)-2-Carboxy-1-(3-pyridiniometh-yl)pyrrolidin-1-ium dichloride hemihydrate.

In the title mol-ecule, C(11)H(16)N(2)O(2) (2+)·2Cl(-)·0.5H(2)O, all N atoms are protonated. In the crystal structure, the organic cation and Cl(-) ions are linked by N-H⋯Cl and O-H⋯Cl hydrogen bonds, forming a one-dimensional infinite ribbon extending parallel to the (110) plane.

2-Amino-5-(1H-tetra-zol-5-yl)pyridin-1-ium nitrate.

In the cation of the title compound, C(6)H(7)N(6) (+)·NO(3) (-), the pyridine and tetra-zole rings are essentially coplanar, exhibiting a dihedral angle of 6.30 (6)°. In the crystal structure, N-H⋯O, N-H⋯N, C-H⋯O and C-H⋯N hydrogen bonds form a three-dimensional network.

Diaqua-[5-(2-pyrid-yl)tetra-zolato-κN,N]manganese(II).

The title compound, [Mn(C(6)H(4)N(5))(2)(H(2)O)(2)], was synthesized by the hydro-thermal reaction of Mn(NO(3))(2) with picolino-nitrile in the presence of NaN(3). The Mn atom lies on an inversion centre. The distorted octa-hedral Mn environment contains two planar trans-related N,N'-chelating 5-(2-pyrid-yl)-tetra-zolate ligands in the equatorial plane and two axial water mol-ecules. O-H⋯N hydrogen bonds generate an infinite three-dimensional network.

catena-Poly[zinc(II)-bis-[µ-5-(2-amino-phenyl)tetra-zolato]-κN,N:N;κN:N,N].

The polymeric title compound, [Zn(C(7)H(6)N(5))(2)](n), was synthesized by the hydro-thermal reaction of Zn(NO(3))(2) with 2-amino-benzonitrile in the presence of NaN(3). The zinc(II) metal centre displays a distorted octa-hedral coordination environment provided by N atoms of two bidentate chelating and two monodentate 5-(2-amino-phen-yl)tetra-zolate ligands. These ligands act as bridges, linking adjacent Zn atoms into polymeric criss-crossed chains parallel to the [110] and [10] directions. Intra-chain N-H⋯N hydrogen-bonding inter-actions are observed.

2-Amino-5-cyano-pyridinium chloride.

In the crystal structure of the title compound, C(6)H(6)N(3) (+)·Cl(-), cohesion is maintained by cation-anion N-H⋯Cl and cation-cation N-H⋯N hydrogen bonds, which link the ions into a three-dimensional network.

3-Cyano-anilinium chloride.

In the title salt, C(7)H(7)N(2) (+)·Cl(-), all non-H atoms of the cation are essentially coplanar (r.m.s. deviation = 0.005 Å). In the crystal structure, the organic cations and chloride ions are linked to form a two-dimensional network parallel to the (001) plane by N-H⋯Cl hydrogen bonds.

(S)-1-Methoxy-carbonyl-2-(4-nitro-phen-yl)ethanaminium chloride.

The title compound, C(10)H(13)N(2)O(4) (+)·Cl(-), comprises a Cl(-) anion and a protonated aminium cation. The crystal packing is stabilized by cation-anion N-H⋯Cl hydrogen bonds and N-H⋯O hydrogen bonds, building an infinite two-dimensional network parallel to the (001) plane. The S absolute configuration at the chiral center was deduced from the synthetic pathway and confirmed by the X-ray analysis.

2-Cyano-anilinium nitrate.

In the title compound, C(7)H(7)N(2) (+)·NO(3) (-), all atoms of the cation, with the exception of two H atoms of the NH(3) group, lie on a mirror plane, while the anion lies across this plane with the N and one O atom on the mirror plane. In the crystal structure, the organic cations and NO(3) (-) anions are linked by N-H⋯N and N-H⋯O hydrogen bonds, forming a two-dimensional network parallel to (100).

2-(2H-Tetra-zol-5-yl)pyridinium chloride.

In the title compound, C(6)H(6)N(5) (+)·Cl(-), the pyridinium and tetra-zole rings are essentially coplanar. The pyridine N atoms are protonated. In the crystal structure, mol-ecules are connected via N-H⋯Cl, C-H⋯Cl, C-H⋯N and N-H⋯N hydrogen bonds into layers that are parallel to the (001) plane. There are two crystallographically independent mol-ecules in the asymmetric unit which are located on mirror planes.

2-Amino-5-(1H-tetra-zol-5-yl)pyridinium chloride.

In the title salt, C(6)H(7)N(6) (+)·Cl(-), there are two organic cations with similar conformations and two chloride anions in the asymmetric unit. The pyridine and tetra-zole rings are essentially coplanar in each cation, with dihedral angles of 4.94 (15) and 5.41 (14)°. The pyridine N atoms are protonated. The crystal packing is stabilized by N-H⋯N and N-H⋯Cl hydrogen bonds, forming an infinite sheets parallel to the (101).