Dynamics of ion diffusional motion in ionic liquid 2, 3-dimethyl-1-hexylimidazolium bis(trifluoromethanesulfonyl)imide

摘要

Ionic Liquid 2,3-dimethyl-1-hexylimidazolium bis(trifluoromethanesulfonyl)imide (DMHxImTFSI) has been synthesized and ~1H and ~(19)F NMR investigations have been carried out to study the ion dynamics of mobile species in the temperature range of 100-400 K. Different ion transport parameters viz. jump frequency (v), diffusion coefficient (d), conductivity (σ_(NMR)) have been calculated from NMR data and their variation with temperature has been studied. It has been observed that at low temperature ionic liquid is present in static lattice state. As the temperature increases motional narrowing of 1H and 19F NMR lines begin above 200 K which marks the onset of long range translational motion. Above 200K the jump frequency of the order of 10~9-10~(10) rad sec~(-1) has been observed.