Novel Lewis-base ionic liquids replacing typical anions

We have synthesized two kinds of new Lewis-base ionic liquids (ILs); one is based oil the relatively strong Lewis basic acetate anion, and the other is a salt composed of a mono-alkylated diamine such that the Lewis base site is incorporated in the cation. I-Octyl-4-aza-1-azonia-bicyclo[2.2.2]octane bis(trifluoromethinesulfonyl)amide, [C(8)dabco]TFSA, and N-butyl-N-methylpyrrolidinium acetate, [P-1,P-4]OAc, melted into fluid liquids at 26 and 81 degrees C, respectively. The thermal decomposition of [p(1,4)]OAc started at around 150 degrees C, whereas the thermal stability of [Csdabco]TFSA was almost equal to that of typical TFSA-based ILs in spite of the Lewis base site. This suggests that if the Lewis base site is incorporated into the cation the IL call maintain higher thermal stability. In addition, as a further result of the presence of the basic nitrogen, [C8dabco]TFSA can dissolve hydrated Cu(NO3)(2) whereas the other TFSA-based ILs cannot. (c) 2006 Elsevier Ltd. All rights reserved.