Electrical Conductivities, Viscosities, and Densities of N-Acetoxyethyl-N,N-dimethyl-N-ethylammonium and N,N-Dimethyl-N-ethyl-N-methoxyethoxyethylammonium Bis(trifluoromethanesulfonyl)amide and Their Nonfunctionalized Analogues

The temperature dependences of the density, viscosity, and electrical conductivity were investigated in four ammonium ionic liquids with the bis(trifluoromethanesulfonyl)amide anion ([Tf 2 N] − ). The cations for the ionic liquids were N -acetoxyethyl- N, N -dimethyl- N -ethylammonium ([N 112,2OCO1 ] + ), N, N -dimethyl- N -ethyl- N -methoxyethoxyethylammonium ([N 112,2O2O1 ] + ), N, N -dimethyl- N -ethyl- N -pentylammonium ([N 1125 ] + ), and N, N -dimethyl- N -ethyl- N -heptylammonium ([N 1127 ] + ). Measurements were performed over the temperature range T = (273.15 to 363.15) K at atmospheric pressure. The densities were fitted to quadratic functions of temperature. The ionic liquids with the functionalized cations ([N 112,2OCO1 ] + and [N 112,2O2O1 ] + ) have the higher densities than the corresponding counterparts with the nonfunctionalized cations ([N 1125 ] + and [N 1127 ] + ). The viscosities and electrical conductivities were analyzed using the Litovitz and Vogel–Fulcher–Tamman equations. The ester functionalized ionic liquid, [N 112,2OCO1 ][Tf 2 N], has poorer transport properties (that is, higher viscosity and lower electrical conductivity) than the nonfunctionalized [N 1125 ][Tf 2 N], whereas the ether functionalized ionic liquid, [N 112,2O2O1 ][Tf 2 N], has superior transport properties to its analogue, [N 1127 ][Tf 2 N]. Empirical Walden plots (double logarithmic graph of molar conductivity vs reciprocal viscosity) give straight lines with slopes less than unity.