In the title salt, C19H15N4 +·Br−, the central imidazole ring makes dihedral angles of 83.1 (2) and 87.6 (2)° with the terminal benzene rings. The dihedral angle between the terminal benzene rings is 6.77 (19)°; the cyanide substituents have an anti orientation. In the crystal, the cations and anions are linked via C—H⋯N and C—H⋯Br hydrogen bonds, forming sheets lying parallel to the ac plane.

In the title compound, C12H12N3 +·PF6 −, the hexa­fluoro­phosphate anion is disordered over two orientations with refined site occupancies of 0.8071 (17) and 0.1929 (17). The dihedral angle between the imidazole and benzene rings in the cation is 71.26 (7)°. In the crystal, the cations and anions are linked by C—H⋯F and C—H⋯N hydrogen bonds into a three-dimensional network.

The title compound, C5H5Cl5N5P3, crystallizes as a zwitterion in which the pyridine N atom is protonated. An S(6) ring motif is formed via an intra­molecular C—H⋯N hydrogen bond. The triaza­triphosphinine ring adopts an envelope conformation, with one N atom displaced by 0.145 (1) Å from the other atoms. In the crystal, N—H⋯N and C—H⋯N hydrogen bonds link the mol­ecules into centrosymmetric dimers containing one R 2 2(7) ring motif and two R 2 2(8) ring motifs.