Identification of radiolytic products of [C(4)mim][PF6] under gamma-irradiation

The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate ([C(4)mim][PF6]) were identified by analysing water-washed samples of gamma-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C(4)mim][PF6], and their radiation chemical yields were quantified by F-19 NMR (G(F-) = 0.14 mu mol/J, G(HOP(O)F-2) = 0.053 mu mol/J). Compared to [C(4)mim][NTf2], [C(4)mim][PF6] shows better radiation stability.