Synthesis and Characterization of Imidazolium Salts Bearing Fluorinated Anions

Abstract The reaction of 1‐methylimidazole and α,α‐dibromo‐ p ‐xylene was followed by a metathesis reaction with fluorinated anion sources, which yielded new fluorinated imidazolium salts [C 6 H 4 (CH 2 (C 4 H 6 N 2 ) 2 ] 2+ 2[ A ] – where A = BF 4 ( 2 ), PF 6 ( 3 ), CF 3 SO 3 ( 4 ), and CF 3 COO ( 5 ). The compounds were characterized by 1 H‐, 13 C‐, 19 F‐, 31 P NMR, and IR spectroscopy. Single crystal X‐ray diffraction data of compounds 2 , 3 , and 4 were also reported, whereas compound 5 was found to be a liquid. The solid compounds crystallized in the monoclinic P 2 1 / c space group and have similar crystallographic parameters. The study revealed that the different fluorinated anions affected the spatial arrangement of atoms and the extent of cation–anion interactions, hence, influenced the stability and coordination properties of the imidazolium salts. A trend was observed which related the strength of cation–anion interaction to physical properties such as melting point.