In the title compound, C(14)H(14)N(+)·I(-), the cation exists in an E configuration with respect to the ethenyl bond and is slightly twisted, the inter-planar angle between the pyridinium and phenyl rings of the cation being 4.8 (2)°. In the crystal packing, the cations are stacked in an anti-parallel fashion along the a axis by a π-π inter-action involving both pyridinium and phenyl rings; the...

Ab initio calculations on pyridine and pyridinium analogues of m-xylylene indicate that the neutral heterocycle is essentially equivalent to benzene as a ferromagnetic coupling unit, while the cationic pyridiniums behave much differently. Depending on the substitution pattern, a protonated pyridine can serve as a ferromagnetic coupling unit or an antiferromagnetic coupling unit. Both valence bo...

In the title compound, C(19)H(21)N(2)O(2) (+)·C(2)H(3)O(2) (-), the 1H-indole ring system is essentially planar [maximum deviation = 0.0257 (14) Å] and forms a dihedral angle of 87.92 (7) Å with the benzene ring attached to the tetra-hydro-pyridinium fragment. The tetra-hydro-pyridinium ring adopts a half-chair conformation. In the crystal, cations and anions are linked by inter-ionic N-H⋯O, C-...

The crystal structure of the title compound, 2C(5)H(8)N(3) (+)·C(6)H(8)O(4) (2-)·C(6)H(10)O(4)·2H(2)O, consists of amino-pyridinium cations, adipate dianions, adipic acid mol-ecules and disordered solvent water mol-ecules [occupancies 0.50 (4) and 0.50 (4)]. Both the adipate and adipic acid are located across inversion centres. Eight-membered hydrogen-bonded rings exist involving amino-pyridini...

In the title compound, C(5)H(8)N(3) (+)·C(24)H(20)B(-)·C(20)H(18)N(6), the 1,2-bis-(5,7-dimethyl-1,8-naphthyridin-2-yl)diazene mol-ecule is essentially planar (r.m.s. deviation = 0.0045 Å) and aligned in nearly coplanar manner with the 2,6-diamino-pyridinium ion, making a dihedral angle of 5.19 (5)°. The diamino-pyridine mol-ecule is protonated on the central pyridine N atom and the B atom bear...

In the title compound, C(5)H(8)N(3) (+)·C(7)H(5)O(2) (-), the pyridine N atom is protonated. The carboxyl-ate group of the benzoate anion is twisted away from the attached ring by 10.91 (9)°. In the crystal structure, N-H⋯O hydrogen bonds between 2,3-diamino-pyridinium cations and benzoate anions, and π-π inter-actions between the pyridinium rings [centroid-centroid distance = 3.6467 (9) Å] for...

The title compound, {(C6H8N)[AgWSe4]·C6H7N} n , consists of anionic [WAgSe4] n chains, 2-methyl-pyridinium cations and neutral 2-methyl-pyridine mol-ecules. The Se atoms bridge the Ag and W atoms, forming a polymeric chain extending along the b-axis direction. Both the Ag and W atoms are located on a twofold rotation axis and each metal atom is coordinated by four Se atoms in distorted tetra-he...

In the title compound, (C(7)H(11)N(2))(2)[ZnCl(4)], [ZnCl(4)](2-) anions and 4-(dimethyl-amino)-pyridinium cations are held together by various inter-molecular inter-actions including Coulombic attraction, hydrogen bonding and π-π stacking inter-actions. Three Cl atoms of the [ZnCl(4)](2-) tetra-hedron act as acceptors in N-H⋯Cl hydrogen bonds. The hydrogen bonds, both of which are bifurcated, ...

In the crystal structure of the title compound, (C7H11N2)2[Mn(NCS)4(C7H10N2)2], the manganese(II) cations are coordinated by four N-bonded thio-cyanate anions and two N-bonded 4-(dimethyl-amino)-pyridine ligands into discrete complex dianions. For charge balance, two 4-(dimethylamino)pyridine counter cations are present, which do not coordinate to the metal cation. The asymmetric unit consists ...

In the title compound, C(5)H(8)N(3) (+)·C(7)H(5)O(2) (-)·C(7)H(6)O(2), the carboxyl and carboxyl-ate groups are twisted away from their attached benzene rings by 10.75 (7) and 20.33 (6)°, respectively. In the crystal structure, the 2,3-diamino-pyridinium cations, benzoate anions and benzoic acid mol-ecules are linked into a two-dimensional network parallel to (001) by O-H⋯O, N-H⋯O and C-H⋯O hyd...