(±)-5-Ethyl-2-(4-isopropyl-4-methyl-5-oxo-4,5-dihydro-1H-imidazol-2-yl)nicotinic acid

2-(3-Nitro-phen-yl)-4,5-diphenyl-1H-imidazol-3-ium nitrate

In the cation of the title compound, C₂₁H₁₆N₃O₂⁺·NO₃⁻, the N atom in the 3-position of the imidazole ring is protonated. The three pendant aromatic rings are twisted from the plane of the imidazolium ring by dihedral angles of 22.75 (1), 79.63 (1) and 29.65 (1)°. In the crystal structure, N—H⋯O hydrogen bonds link the mol­ecules, forming an infinite one-dimensional chain parallel to the b axis.

2-(4-Nitro-phen-yl)-4,5-diphenyl-1H-imidazol-3-ium chloride

In the cation of the title compound, C(21)H(16)N(3)O(2) (+)·Cl(-), the N atom in the 3-position of the imidazole ring is protonated. The three pendant aromatic rings are twisted from the plane of the imidazolium ring by dihedral angles of 31.69 (14)°, 31.09 (14)° and 34.77 (14)°. In the crystal structure, N-H⋯Cl hydrogen bonds link the mol-ecules, forming a chain parallel to the b axis.

4,5-Diphenyl-2-p-tolyl-1H-imidazol-3-ium nitrate

In the cation of the title compound, C₂₂H₁₉N₂⁺·NO₃⁻, the N atom in the 3-position of the imidazole is protonated. The three pendant aromatic rings are twisted from the plane of the imadazolium ring by dihedral angles of 38.1 (1), 43.74 (9) and 20.4 (1)°. In the crystal structure, N—H⋯O and N—H⋯(O,O) hydrogen bonds link the mol­ecules to form an infinite one-dimensional chain parallel to the c axis.

2-(3-Nitro-phen-yl)-4,5-diphenyl-1H-imidazol-3-ium chloride

The title compound, C₂₁H₁₆N₃O₂⁺·Cl⁻, contains two organic cations with similar conformation and two chloride ions in the asymmetric unit. The imidazole and benzene rings are twisted with respect to each other [dihedral angles of 24.05 (16), 24.31 (16) and 50.38 (13) in one cation and 27.70 (15), 25.07 (16) and 45.86 (14)° in the other]. The crystal packing is stabilized by N—H⋯Cl hydrogen bonds, forming an infinite one-dimensional chain parallel to the c axis.