No Fear of Perfluorinated Peroxides: Syntheses and Solid-State Structures of Surprisingly Inert Perfluoroalkyl Peroxides.

We report on the solid-state structures of bis(nonafluoro-tert-butyl) peroxide [(F3 C)3 CO]2 and bis(undecafluoro-2-methyl-2-butyl) peroxide [(C2 F5 )(F3 C)2 CO]2 . These peroxides were prepared from the corresponding hypofluorites and fluorinated silver wool. The solid-state structures obtained after in situ crystallisation show unusual COOC dihedral angles of 180°, as well as elongated O-O bonds because of the bulky perfluorinated alkyl groups. The perfluorinated alkyl peroxides are insensitive to both impact (>40 J) and friction (>360 N), and resistant towards mineral acids (HX; X=F, Cl, Br) and elemental halogens (X2 ). Ferrocene is oxidized by [(F3 C)3 CO]2 to [FeIII Cp2 ][OC(CF3 )3 ].