Find in Library

The title N-heterocyclic carbene compound, C21H22N42+·2PF6−, crystallizes as an inversion twin. There are two independent N-heterocyclic carbene dications (A and B) and four independent hexafluorophosphate anions in the asymmetric unit. The cations are L-shaped with the benzene rings being inclined to one another by 88.82 (16)° in cation A and 87.03 (16)° in cation B. The imidazole rings make dihedral angles of 35.7 (2) and 32.83 (18)° with the attached benzene rings in cation A, and 30.14 (19) and 31.96 (18)° in cation B. In the crystal, the cations are linked via C—H...F hydrogen bonds, forming a three-dimensional network. π–π interactions involving the benzene and imidazole rings [centroid–centroid distances = 3.602 (2) and 3.723 (2) Å] and C—H...π interactions are also present.