N,N'-Bis(2-amino-benz-yl)ethane-1,2-diaminium dinitrate.

In the title salt, C16H24N4 (2+)·2NO3 (-), both the cation and anion are placed in general positions, although the cation displays non-crystallographic inversion symmetry, with the aliphatic chain extended in an all-trans conformation. The benzene rings are almost parallel, with a dihedral angle between their mean planes of 3.3 (6)°. The nitrate ions are placed in the vicinity of the protonated amine groups, forming efficient N-H⋯O inter-ion hydrogen bonds. Each nitrate ion in the asymmetric unit bridges two symmetry-related cations, forming an R 4 (4)(18) ring, a common motif in organic ammonium nitrate salts. This results in the formation of chains along [010] with alternating cations and anions. The neutral amine groups are involved in slightly weaker N-H⋯O hydrogen bonds with the nitrate O atoms, and there are also a number of C-H⋯O hydrogen bonds present. The resulting supra-molecular structure is based on a two-dimensional network extending in the ab plane.

N,N'-Bis(2-amino-benz-yl)ethane-1,2-diaminium bis-(4-methyl-benzene-sulfonate).

The title salt, C(16)H(24)N(4) (2+)·2C(7)H(7)O(3)S(-), crystallizes with the dication situated on an inversion center and the anion in a general position. The cation contains two ammonium and two free amine groups, and the observed conformation for the chain linking the benzene rings is different from that found in the free tetra-amine and in the fully protonated tetra-amine. All amine and ammonium H atoms of the cation form hydrogen bonds with eight symmetry-related anions, using the sulfonate O atoms as acceptors. This arrangement for the ions precludes any π-π contacts between benzene rings in the crystal.

N,N'-Bis(2-aza-niumylbenz-yl)ethane-1,2-diaminium tetra-chloride.

The title compound, C(16)H(26)N(4) (4+)·4Cl(-), is based on a fully protonated tetra-amine. In the cation, both benzene rings are connected by an all-trans chain, and the rings are almost parallel, with an angle between the mean planes of 8.34 (12)°. The benzene rings are arranged in such a way that the NH(3) (+) substituents are oriented cis with respect to the central chain. This arrangement is a consequence of multiple N-H⋯Cl hydrogen bonds, involving all N-H groups in the cation and the four independent Cl(-) anions. These contacts have strengths ranging from weak to strong (based on H⋯Cl separations), and generate a complex three-dimensional crystal structure with no preferential crystallographic orientation for the contacts.

2,2'-(2,6-Pyridinedi-yl)diquinoline.

The title mol-ecule, C(23)H(15)N(3), is a terpyridine derivative resulting from the Friedländer annulation between 2,6-diacetyl-pyridine and N,N'-bis-(2-amino-benz-yl)ethyl-ene-di-amine. The asymmetric unit contains one half-mol-ecule, the complete mol-ecule being generated by a mirror plane (one N atom and one C atom lie on the plane). The mol-ecule, although aromatic, is deformed from planarity as a result of crystal packing forces: mol-ecules are stacked along the short c axis, with a short separation of 3.605 (1) Šbetween the mean planes. The bent mol-ecular shape is reflected in the dihedral angle of 16.10 (5)° between the essentially planar quinoline groups. In addition to π⋯π inter-actions, the crystal structure features weak inter-stack C-H⋯N contacts involving atoms of the central pyridine rings which lie in a common crystallographic m plane.

N,N'-Bis(2-ammonio-benz-yl)ethane-1,2-diammonium-nitrate-perchlorate (1/1.5/2.5).

The title compound, C(16)H(26)N(4) (4+)·2.5ClO(4) (-)·1.5NO(3) (-), is an organic salt in which the cation is a fully protonated tetra-mine. The cation lies on an inversion center and, as a consequence, both benzene rings are parallel. The central chain is found in an all-trans arrangement, a conformation different from that observed in the crystal structure of the non-protonated mol-ecule. The charges are balanced by a mixture of nitrate and perchlorate ions. One site is occupied by an ordered perchlorate ion, while the other contains both nitrate and perchlorate ions, with occupancies of 0.75 and 0.25, respectively. In the crystal, the NH(2) (+) groups of the cation form N-H⋯O hydrogen bonds with the anions. The NH(3) (+) groups also behave as donor groups, allowing the building of chains along [100], alternating cations and disordered anions being connected via N-H⋯O hydrogen bonds.