In the cation of the title salt, C6H7N2S+·SCN−, the C=S bond is oriented trans with respect to the C—C=N fragment in the pyridine ring. The planes of the aromatic ring and the thio­amide fragment of the cation make a dihedral angle of 38.31 (4)°. In the crystal, the components are linked by N—H⋯S and N—H⋯N, hydrogen bonds, forming a two-dimensional network parallel to (10-1).

In the title hydrated mol­ecular salt, C12H14N2S2 2+·2Cl−·2H2O, the dihedral angle between the benzene rings in the dication is 9.03 (17)° and the C—S—S—C torsion angle is 96.8 (2)°. The crystal packing can be described as alternating organic and anionic water layers lying parallel to (100), which are linked by N—H⋯Cl and N—H⋯O hydrogen bonds. O—H⋯Cl hydrogen bonds and aromatic π–π stacking inter­actions [centroid–centroid separation = 3.730 (3) Å] are also observed.

In the title compound, [CoCl2(H2O)4]·2C4H8SO2, the CoII cation is located on the twofold rotation axis and is coordinated by four water mol­ecules and two adjacent chloride ligands in a slightly distorted octa­hedral coordination environment. The cisoid angles are in the range 83.27 (5)–99.66 (2)°. The three transoid angles deviate significantly from the ideal linear angle. The crystal packing can be described as a linear arrangement of complex units along c formed by bifurcated O—H⋯Cl hydrogen bonds between two water mol­ecules from one complex unit towards one chloride ligand of the neighbouring complex. Two solvent mol­ecules per complex are attached to this infinite chain via O—H⋯O hydrogen bonds in which water mol­ecules act as the hydrogen-bond donor and sulfolane O atoms as the hydrogen-bond acceptor sites.