The crystal structures of 1-(4-bromo-2,3,5,6-tetrafluorophenyl)-3-benzyl-methylimidazolium bromides

The crystal structures of 1-(4-bromo-2,3,5,6-tetrafluorophenyl)-2-methyl-3-benzylimidazolium bromide (8) and 1-(4-bromo-2,3,5,6-tetrafluorophenyl)-3-benzyl-4-methylimidazolium bromide (9) have been determined by single crystal X-ray diffraction. Both crystal structures possess C(2)─H⋯Br− hydrogen bonding and C─Br⋯Br− halogen bonding. That of 8 also contains π–π stacking between bromotetrafluorophenyl and phenyl rings, and that of 9 also contains C(1)─H⋯Br− hydrogen bonding and anion–π interactions. The crystal structure of 9 is similar to that of the non-methylated salt, 1-(4-bromo-2,3,5,6-tetrafluorophenyl)-3-benzylimidazolium bromide (4), with columns of alternating parallel bromotetrafluorophenyl rings and bromide