Effect of replacing [NTf2] by [PF6] anion on the [BMIm][NTf2] ionic liquid confined by gold

摘要

The effect of replacing bis(trifluoromethylsulphonyl)imide ([NTf2]) by hexafluorophosphate ([PF6]) in room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulphonyl)imide ([BMIm][NTf2]) confined between two gold interfaces is herein reported through molecular dynamics simulations using all-atom non-polarisable force-fields. Five systems were studied ranging from pure [BMIm][NTf2] to pure [BMIm][PF6], with [PF6] molar fractions of 0, 0.125, 0.25, 0.375 and 0.5. Special attention was drawn to investigate the impact of the [PF6] anion on the IL, in particular on the first layers of the liquid in close contact with the solid gold surface.