1,1',2,2'-Tetra-methyl-3,3'-(p-phenyl-ene-dimethyl-ene)diimidazol-1-ium bis-[bis-(trifluoro-methyl-sulfon-yl)imide]

The cation of the imidazolium-based ionic-liquid title salt, C(16)H(24)N(4) (2+)·2C(2)F(6)NO(4)S(2) (-), lies on a center of inversion; in the cation, the five-membered imidazolium ring is aligned at 84.4 (1)° with respect to the phenyl-ene ring; the angle at the methyl-ene C atom is 113.0 (2)°. In the anion, the negative charge formally resides on the two-coordinate N atom; the S-N-S angle at this atom is 125.2 (1)°.