Liquid Structure of 1-Butyl-3-methylimidazolium Hexafluorophosphate by Neutron Diffraction with H/D Isotopic Substitution Method

The liquid structure of the ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM]PF6, was investigated by neutron diffraction with H/D substitution method, where the hydrogen atoms in the imidazolium ring were partially deuterated. The local structures around the ring hydrogen atoms in liquid are very similar to those estimated from the crystal structure.