Abstract:
A series of highly-fluorinated triaminocycloprope nium salts, with up to six fluorous groups, were prepared and
their properties as ionic liquids investigated. Reaction of
pentachlorocyclopropane or tetrachlorocyclopropene with
bis(2,2,2-trifluoroethyl)amine, HN(CH2CF3)2, occurs in the pres ence of a trialkylamine, NR3, to give cations with two
fluorinated amino groups, [C3(N(CH2CF3)2)2(NR2)]+ (R=Et, Pr,
Bu, Hex), with traces of [C3(N(CH2CF3)2)3]
+. Use of appropriate
reagent ratios and reaction times and subsequent addition of
a dialkylamine, HNR’R”, gives cations with one fluorinated
amino group, [C3(N(CH2CF3)2)(NR2)(NR’R”)]+ ((NR2)(NR’R”)= (NBu2)2, (NEt2)(NPr2), (NBu2)(NBuMe)). These cations were
isolated as chloride salts and some of these were converted
to bistriflamide, dicyanamide and triflate salts to provide ionic
liquids. These salts were characterised by thermal (DSC and
TGA) measurements and miscibility/solubility properties
(determined in a range of solvents). Ionic liquids (ILs) were
also characterised by density, viscosity and conductivity
measurements where possible. X-ray diffraction studies of
chloride salts showed the formation of fluorous regions and
more hydrophilic ionic regions in the solid state.
