Dielectric relaxation and solvation dynamics in a room-temperature ionic liquid: temperature dependence.

摘要: Dielectric relaxation, related polarization and conductivity, solvation dynamics of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate (BMI+PF6–) are studied via molecular computer simulations in temperature range 300 K ≤ T 500 K. Two main bands its dielectric loss spectrum show differing behaviors. As increases, absorption band microwave region shifts to higher frequencies rapidly, whereas location bimodal far-IR remains nearly unchanged. Their respective intensities tend decrease increase. The static constant BMI+PF6– is found weakly with T. ultrafast inertial component largely unchanged, while their dissipative relaxation becomes faster. Roles played by ion reorientations translations governing dynamic properties examined. A brief comparison available experimental results also made.