In the anion of the title mol-ecular salt, C(4)H(12)N(2) (2+)·C(11)H(10)O(6) (2-), the two acetate groups form torsion angles of 74.1 (1) and 7.1 (1)° with the central benzene ring, and the cation exhibits a chair conformation. In the crystal, N-H⋯O hydrogen bonds link the components into a two-dimensional supra-molecular network lying parallel to the ab plane. A number of C-H⋯O inter-actions c...

Pyrazine and 5-sulfosalicylic acid crystallize from a methanol solution containing water as the title salt, C(4)H(6)N(2) (2+)·2C(7)H(5)O(6)S(-)·2H(2)O. The pyrazine-diium cation sits on an inversion center. The component ions and water mol-ecules are linked by inter-molecular O-H⋯O, N-H⋯O and C-H⋯O hydrogen bonds into layers running parallel to the (10) plane.

In the crystal structure of the title salt, (C10H10N2)[ZnCl4], the bi-pyridine-diium dication is not planar, with a dihedral angle of 37.21 (9)° between the planes of the two pyridine rings. In the crystal, the slightly distorted [ZnCl4](2-) anions are packed into rods parallel to [001], with the organic cations arranged in corrugated layers parallel to (100). Cations and anions are linked thro...

In the title compound, 2C12H20N2 (2+)·2H3O(+)·P6O18 (6-)·2H2O, a protonated water mol-ecule bridges the centrosymmetrical anionic P6O18 ring via O-H⋯O hydrogen bonds. The centrosymmetric hydrogen-bonded rings formed by four oxonium cations and four phosphate anions can be described by an R 4 (8)(36) graph-set motif. The ring motifs are connected by hydrogen bonds into inorganic layers perpendic...

In the title hydrated mol-ecular salt, C(6)H(16)N(2) (+)·2PF(6) (-)·2H(2)O, the complete 1,4-dimethyl-piperazine-1,4-diium dication is generated by crystallographic inversion symmetry and both C-N bonds are in equatorial orientations. In the crystal, the components are linked by O-H⋯F and N-H⋯O hydrogen bonds but there are no direct links between cations and anions.

By combining a viologen unit and a 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) radical in one single combi-molecule, an artificial bipolar redox-active material, 1-(4-(((1-oxyl-2,2,6,6-tetramethylpiperidin-4-yl)oxy)carbonyl)benzyl)-1'-methyl-[4,4'-bipyridine]-1,1'-diium-chloride (VIOTEMP), was created that can serve as both the anode (-0.49 V) and cathode (0.67 V vs. Ag/AgCl) in a water-based r...