3,3'-Dimethyl-1,1'-[2,2'-bipyridine-5,5'-diylbis(methyl-ene)]diimidazol-3-ium bis-(hexa-fluoro-phosphate).

The title compound, C(20)H(22)N(6) (2+)·2PF(6) (-), was prepared by the reaction of 5,5'-bis-(bromo-meth-yl)-2,2'-bipyridine with 1-methyl-imidazole. The main mol-ecule lies on an inversion center located at the mid-point of the C-C bond joining the two pyridine rings. The asymmetric unit therefore contains one half-mol-ecule and one hexa-fluoro-phosphate anion. The dihedral angle between the pyridine and imidazole rings is 76.93 (7)°. In the crystal, weak inter-molecular C-H⋯F hydrogen bonds contribute to the stabilization of the packing.