In the title mol­ecular salt, C18H24N4 2+·2PF6 −, the complete dication is generated by a crystallographic inversion centre. The central benzene ring makes a dihedral angle of 77.19 (9)° with each of the imidazole rings. In the crystal, C—H⋯F inter­actions link the cations and anions into layers lying parallel to the bc plane. The hexa­fluoro­phosphate anion is disordered over two sets of sites in a 0.520 (11):0.480 (11) ratio.

In the title compound, C20H28N4 2+·2PF6 −, the dihedral angles between the benzene ring and the imidazole rings are 70.18 (11) and 69.83 (11)°, while the imidazole rings form a dihedral angle of 40.52 (12)°. In the crystal, weak C—H⋯F inter­actions link the mol­ecules into a two-dimensional network parallel to (001). A π–π inter­action with a centroid–centroid distance of 3.601 (1) Å is also observed in the crystal structure.

In the title compound, C32H36N4 2+·2PF6 −, the cation and the anions each have crystallographic twofold rotation symmetry. The benzimidazole ring is almost planar [r.m.s. deviation = 0.0161 (1) Å] and makes a dihedral angle of 5.77 (4)° with its symmetry-related component and a dihedral angle of 80.96 (5)° with the central benzene ring. The cyclo­pentyl ring adopts a half-chair conformation. In the crystal, mol­ecules are linked into a three-dimensional network through C—H⋯F hydrogen bonds. A C—H⋯π inter­action is also observed.

In the title compound, C26H28N4 2+·2PF6 −, the complete cation is generated by a crystallographic twofold axis. The benz­imidazole ring is almost planar (r.m.s. deviation = 0.0207 Å) and makes dihedral angles of 50.12 (2)° with its symmetry-related component and 65.81 (2)° with the central benzene ring. In the crystal, mol­ecules are linked into a three-dimensional network by C—H⋯F inter­actions. A π–π inter­action with a centroid–centroid distance of 3.530 (1) Å is observed. Four F atoms of the hexa­fluoro­phosphate anion are disordered over two sets of sites in a 0.889 (6):0.111 (6) ratio.

In the title hydrated mol­ecular salt, C38H52N4 2+·2Br−·H2O, the central benzene ring of the dication makes dihedral angles of 89.47 (13) and 72.69 (12)° with the pendant benzimidazol-3-ium rings. The conformations of the octyl side chains are completely different. In the crystal, the components are linked by O—H⋯Br, C—H⋯Br and C—H⋯O hydrogen bonds into a two-dimensional network lying parallel to the ac plane. Aromatic π–π stacking inter­actions are also observed [shortest centroid-to-centroid separation = 3.5047 (16) Å].

The asymmetric unit of the title compound, C28H32N4 2+·2Cl−·2H2O, contains half of a 3,3′-[1,4-phenyl­enebis(methyl­ene)]bis­(1-propyl­benzimidazolium) cation, one chloride anion and one water mol­ecule. The complete cation is generated by a crystallographic inversion center. The central benzene ring forms a dihedral angle of 66.06 (11)° with its adjacent benzimidazolium ring system. In the crystal, the cations, anions and water mol­ecules are linked by O—H⋯Cl, C—H⋯O and C—H⋯Cl hydrogen bonds into a three-dimensional network. The crystal packing is further stabilized by π–π inter­actions, with centroid–centroid distances of 3.5561 (15) and 3.6708 (15) Å.

In the title mol­ecular salt, C26H28N4 2+·2Br−, the central benzene ring makes dihedral angles of 76.75 (11) and 82.40 (10)° with the pendant benzimidazole rings. The corresponding angle between the benzimidazole rings is 57.03 (9)°. In the crystal, the cations and anions are linked via C—H⋯Br hydrogen bonds, forming sheets lying parallel to the bc plane. The crystal structure also features weak C—H⋯π inter­actions.

The asymmetric unit of the title compound, C28H32N4 2+·2Br−·0.5H2O, contains one 3,3′-[1,2-phenyl­enebis(methyl­ene)]bis­(1-propyl­benzimidazolium) cation, two bromide anions and one half-mol­ecule of water. In the crystal, the whole 3,3′-[1,2-phen­yl­enebis(methyl­ene)]bis­(1-propyl­benzimidazolium) cation and one of the bromide anions are each disordered over two positions with site-occupancy ratios of 0.751 (6):0.249 (6) and 0.680 (8):0.320 (8). For the major component of the disordered cation, the central benzene ring forms dihedral angles of 83.6 (5) and 88.2 (4)° with its adjacent imidazole rings, while these angles for the minor component are 89.2 (15) and 84.9 (13)°. In the crystal, the cations and anions are linked by C—H⋯Br hydrogen bonds into dimers and then stacked along the c axis. The crystal packing is further stabilized by C—H⋯π and π–π inter­actions [shortest centroid–centroid distance = 3.646 (4) Å].

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.

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 cation of the title mol­ecular salt, C20H24N4 2+·2PF6 −, the central benzene ring makes dihedral angles of 84.19 (7) and 79.10 (7)° with the pendant imidazole rings. In one of the hexa­fluoro­phosphate anions, the six F atoms are disordered over two sets of sites, with an occupancy ratio of 0.842 (3):0.158 (3). In the crystal, the cations and anions are linked by numerous C—H⋯F hydrogen bonds, thereby forming a three-dimensional network.

The asymmetric unit of the title complex, [Hg(C11H12N2)2](PF6)2, consists of one bis­(1-benzyl-3-methyl­imidazolium)mercury(II) cation, one half of the cation and an additional HgII atom, which lies on an inversion centre, and three hexa­fluorido­phosphate anions. The HgII atoms exist in a linear coordination geometry [C—Hg—C = 178.9 (2) and 180°] formed by two carbene C atoms from the imidazole rings. In the crystal, the cations and anions are connected via C—H⋯F hydrogen bonds, forming a three-dimensional network.

In the title mol­ecular salt, C23H30N4 2+·2PF6 −, the central benzene ring of the cation makes dihedral angles of 89.80 (8) and 85.23 (7)° with the pendant imidazole rings. In the crystal, the cations and anions are linked by numerous C—H⋯F hydrogen bonds, thereby forming a three-dimensional network.

The asymmetric unit of the title compound, C20H28N4 2+·2Br−, consists of half a 3,3′-di-n-propyl-1,1′-[p-phenyl­enenis(methyl­ene)]diimidazolium cation and a bromide anion. The cation is located on an inversion center and adopts an ⋯AAA⋯ trans conformation. In the crystal, the cation is linked to the anions via weak C—H⋯Br hydrogen bonds.

In the title salt, C36H48N4 2+·2Br−·H2O, the central benzene ring makes dihedral angles of 84.77 (9) and 69.92 (7)° with the adjacent imidazole rings. In the crystal, one of the heptyl groups is disordered over two sets of sites with an occupancy ratio of 0.474 (5):0.526 (5). In the crystal, the cations, anions and water mol­ecules are connected via inter­molecular O—H⋯Br, C—H⋯Br and C—H⋯O hydrogen bonds, forming a three-dimensional network.

In the title molecular salt, C31H34N4 2+·2Br−, the central benzene ring makes dihedral angles of 80.47 (12) and 82.78 (12)° with the adjacent imidazole rings. The dihedral angle between the two terminal phenyl rings is 79.16 (13)°. In the crystal, the cations and anions are linked via C—H⋯Br hydrogen bonds, forming supra­molecular chains along the c axis.

In the title molecular salt, C25H38N4 2+·2PF6 −, one of the butyl groups and four F atoms in the basal plane of one of the PF6 − octa­hedra are disordered over two sets of sites, with occupancy ratios of 0.704 (5):0.296 (5) and 0.71 (3):0.29 (3), respectively. The central benzene ring makes dihedral angles of 85.17 (12) and 81.97 (12)° with the terminal imidazole rings. In the crystal, cations and anions are linked together via inter­molecular C—H⋯F hydrogen bonds forming a three-dimensional network.

In the title compound, K[Ag(C11H12N2)2]2(PF6)3, the 12-coordinate potassium cation lies on a crystallographic twofold axis and one of the hexa­fluoro­phosphate anions is generated by symmetry. In the complex cation, the AgI ion is coordinated by two C atoms; the two imidazolium rings are orientated at a dihedral angle of 8.14 (14)°. In the 1-benzyl-3-methyl­imidazolium units, the dihedral angles between imidazolium and phenyl rings are 80.47 (15) and 76.53 (14)°. The F atoms of the general-position hexa­fluoro­phosphate anion are disordered over two sets of sites in a 0.767 (17):0.233 (17) ratio. In the crystal, the hexa­fluoro­phosphate anions link the cations into three-dimensional networks via inter­molecular C—H⋯F hydrogen bonds and are further consolidated by π–π stacking [centroid–centroid distances = 3.5518 (15) Å] inter­actions.

In the title compound, C20H24N4 2+·2PF6 −, the ethene and 3-allyl­imidazolium moieties of the cation are disordered over two positions with refined site occupancies of 0.664 (19):0.336 (19) and 0.784 (7):0.216 (7), respectively, whereas four F atoms of one hexa­fluoridophosphate anion and all atoms in the other hexa­fluoridophosphate anion are disordered over two positions with refined site occupancies of 0.764 (5):0.2365) and 0.847 (9):0.153 (9), respectively. The benzene ring is inclined at angles of 78.2 (3), 81.3 (4) and 73.9 (12)° with the 1H-imidazol-3-ium ring and the major and minor components of the disordered 1H-imidazol-3-ium ring, respectively. In the crystal, the hexa­fluoridophosphate anions link the cations into two-dimensional networks parallel to (001) via inter­molecular C—H⋯F hydrogen bonds. The crystal structure is further consolidated by π–π [centroid–centroid distance = 3.672 (3) Å] and C—H⋯π inter­actions.

In the title compound [systematic name: 3,3′-Dibutyl-1,1′-(5-methyl-m-phenyl­enedimethyl­ene)diimidazol-1-ium bis­(hexa­fluoridophosphate)], C23H34N4 2+·2PF6 −, the imidazole rings are inclined at angles of 68.06 (7) and 75.05 (8)° with respect to the central benzene ring. In the crystal, mol­ecules are linked into one-dimensional columns along [010] via weak inter­molecular C—H⋯F hydrogen bonds. The crystal structure is further consolidated by weak C—H⋯π(arene) inter­actions. One of the n-butyl groups is disordered over two sites with refined occupancies of 0.694 (5) and 0.306 (5). In addition, four of the F atoms of one of the PF6 − cations are disordered over two sites with occupancies of 0.64 (3) and 0.36 (3).

The asymmetric unit of the title complex, [Ag2(C22H30N4)2](PF6)2, consists of one AgI ion, one 1,4-bis­[(3-butyl­imidazolium-1-yl)meth­yl]benzene ligand and one discrete hexa­fluoridophosphate anion. The formula unit is generated by an inversion center. The unique AgI ion is coordinated by two C atoms of two heterocyclic carbene ligands in an essentially linear geometry. In the crystal structure, cations and anions are linked through weak C—H⋯F hydrogen bonds, forming a three-dimensional network.

The asymmetric unit of the title N-heterocyclic carbene compound, C22H32N4 2+·2PF6 −, consists of one half of the N-heterocyclic carbene dication and one hexa­fluoro­phosphate anion. The dication lies across a crystallographic inversion center. The imidazole ring is twisted away from the central benzene ring, making a dihedral angle of 76.23 (6)°. The hexa­fluoro­phosphate anions link the cations into a three-dimensional network via inter­molecular C—H⋯F hydrogen bonds. A weak C—H⋯π inter­action further stabilizes the crystal structure.

The asymmetric unit of the title N-heterocyclic carbene compound, C17H22N4 2+·2PF6 −, consists of one N-heterocyclic carbene dication and two hexa­fluoro­phosphate anions. The two imidazole rings are twisted away from but to the same side of the central toluene ring, making dihedral angles of 76.69 (7) and 78.03 (7)° with the central ring. In the crystal, the components are linked by C—H⋯F interactions, generating a three-dimensional network.