Perfluorophenyl 2 2 2-trifluoroacetate July 8, 2019 16 32 64 128 Perfluorophenyl 2 2 2 trifluoroacetate Perfluorophenyl 2 2 2 trifluoroacetate density Perfluorophenyl 2 2 2 trifluoroacetate cas no 2 2-difluoro-2-(triphenylphosphonio)acetate