The present invention relates to compositions of matter that are useful as ionic liquids. The compositions of the invention are based on an N-substituted pyrrolidinone, said pyrrolidinone having a pendant ammonium cation that is separated from the pyrrolidone ring by a variable length alkyl spacer.
1. A compound of the Formula:
wherein:
(i) Z is —(CH 2 ) n —, wherein n is an integer from 2 to 12;
(ii) R 2 , R 3 and R 4 taken independently are H, —CH 3 , —CH 2 CH 3 or C 3 to C 6 straight-chain or branched monovalent alkyl; and
(iii) A − is an anion selected from the group consisting of [BF 4 ] − , [PF 6 ] − , [SbF 6 ] − , [CH 3 CO 2 ] − , [HSO 4 ] − , [CF 3 SO 3 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − , [(CF 3 SO 2 ) 2 N] − , [AlCl 4 ] − , [CF 3 CO 2 ] − , [NO 3 ] − , [SO 4 ] 2− , Cl − , Br − , I − , and F − .
2. The compound of claim 1 wherein Z is —(CH 2 ) n —, wherein n is an integer from 2 to 6.
3. The compound of claim 1 wherein the anion is [PF 6 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − or [(CF 3 SO 2 ) 2 N] − .
4. The compound of claim 2 wherein the anion is [PF 5 ] − , [HCF 2 CF 2 SO 3 ] − , [CF 3 HFCCF 2 SO 3 ] − , [HCClFCF 2 SO 3 ] − or [(CF 3 SO 2 ) 2 N] − .