Anion Complexation of Vinylimidazolium Salts and Its Influence on Polymerization

To improve water solubility of 1-butyl-3-vinylimidazolium bis(trifluoromethylsulfonyl)imide ([bvim][Tf 2 N]) the complexation with β-Cyclodextrin (β-CD) was carried out. Investigations of conductivity measurements, NMR and microcalorimetry show that β-CD forms exclusively host−guest complexes with the anion bis(trifluoromethylsulfonyl)imide (Tf 2 N - ). The received spatially separated ion pairs create quasi “naked” vinylimidazolium cations which do not polymerize in water by radical mechanism. Only in the presence of foreign salt is the cation−cation repulsion compensated and polymerization occurs.