Explored routes to unknown polyfluoroorganyliodine hexafluorides, R FIF6

Article abstract of DOI:10.1016/j.jfluchem.2010.07.005

Two routes to R_FIF₆ compounds were investigated: (a) the substitution of F by R_F in IF₇ and (b) the fluorine addition to iodine in R_FIF₄ precursors. For route (a) the reagents C₆F₅SiMe₃, C₆F ₅SiF₃, [NMe₄][C₆F ₅SiF₄], C₆F₅BF₂, and 1,4-C₆F₄(BF₂)₂ were tested. C ₆F₅IF₄ and CF₃CH₂IF ₄ were used in route (b) and treated with the fluoro-oxidizers IF₇, [O₂][SbF₆]/KF, and K₂[NiF ₆]/KF. The observed sidestep reactions in case of routes (a) and (b) are discussed. Interaction of C₆F₅SiX₃ (X = Me, F), C₆F₅BF₂, 1,4-C₆F ₄(BF₂)₂ with IF₇ gave exclusively the corresponding ring fluorination products, perfluorinated cyclohexadiene and cyclohexene derivatives, whereas [NMe₄][C₆F ₅SiF₄] and IF₇ formed mixtures of C ₆F_nIF₄ and C₆F_nH compounds (n = 7 and 9). CF₃CH₂IF₄ was not reactive towards the fluoro-oxidizer IF₇, whereas C₆F ₅IF₄ formed C₆F_nIF₄ compounds (n = 7 and 9). C₆F₅IF₄ and CF ₃CH₂IF₄ were inert towards [O ₂][SbF₆] in anhydrous HF. CF₃CH ₂IF₄ underwent C-H fluorination and C-I bond cleavage when treated with K₂[NiF₆]/KF in HF. The fluorine addition property of IF₇ was independently demonstrated in case of perfluorohexenes. C₄F₉CFCF₂ and IF₇ underwent oxidative fluorine addition at -30 °C, and the isomers (CF ₃)₂CFCFCFCF₃ (cis and trans) formed very slowly perfluoroisohexanes even at 25 °C. The compatibility of IF₇ and selected organic solvents was investigated. The polyfluoroalkanes CF ₃CH₂CHF₂ (PFP), CF₃CH ₂CF₂CH₃ (PFB), and C₄F₉Br are inert towards iodine heptafluoride at 25 °C while CF₃CH ₂Br was slowly converted to CF₃CH₂F. Especially PFP and PFB are new suitable organic solvents for IF₇.