Ambient-temperature molten salts of formula (I): ##STR00001## wherein
Y.sup.+ is a cation selected from the group consisting of an ammonium
ion, a sulfonium ion, a pyridinium ion, a(n) (iso)thiazolium ion, and
a(n) (iso)oxazolium ion that may be optionally substituted with
C.sub.1-10 alkyl and/or C.sub.1-10 alkyl having ether linkage, provided
that the above cation has at least one substituent of --CH.sub.2Rf.sup.1
or --OCH.sub.2Rf.sup.1 (wherein Rf.sup.1 is C.sub.1-10 perfluoroalkyl);
Rf.sup.2 and Rf.sup.3 are independently C.sub.1-10 perfluoroalkyl or may
together form C.sub.1-4 perfluoroalkylene; and X is --SO.sub.2-- or
--CO--.
