Boric Ester-Type Molten Salt via Dehydrocoupling Reaction

Novel boric ester-type molten salt was prepared using 1-(2-hydroxyethyl)-3-methylimidazolium chloride as a key starting material. After an ion exchange reaction of 1-(2-hydroxyethyl)-3-methylimidazolium chloride with lithium (bis-(trifluoromethanesulfonyl) imide) (LiNTf(2)), the resulting 1-(2-hydroxyethyl)-3-methylimidazolium NTf(2) was reacted with 9-borabicyclo[3.3.1]nonane (9-BBN) to give the desired boric ester-type molten salt in a moderate yield. The structure of the boric ester-type molten salt was supported by (1)H-, (13)C-, (11)B- and (19)F-NMR spectra. In the presence of two different kinds of lithium salts, the matrices showed an ionic conductivity in the range of 1.1 × 10(−4)–1.6 × 10(−5) S cm(−1) at 51 °C. This was higher than other organoboron molten salts ever reported.