Syntheses and properties of FOIF4O, ClOIF4O, HOIF4O, and tetrafluoroperiodates

Article abstract of DOI:10.1021/ic50221a034

Mixtures of cis- and trans-CsIF₄O₂ were prepared by the interaction of CsIO₄ with either anhydrous HF, BrF₅, ClF₃, ClF₅, or F₂. The vibrational spectra of these mixtures were recorded, and partial assignments are given for cis- and trans-IF₄O₂^-. The assignments for trans-IF₄O₂^- were supported by a normal-coordinate analysis. The CsIF₄O₂ salt dissolves in CH₃CN with the formation of IF₄O₂^- anions but undergoes solvolysis in anhydrous HF with formation of HOIF₄O. An improved synthesis of HOIF₄O from CsIF₄O₂ and BiF₅ in anhydrous HF is reported, and its Raman and ¹⁹F NMR spectra were recorded. The interaction of CsIF₄O₂ with NF₄SbF₆ in anhydrous HF results in solutions containing NF₄⁺, HF₂^-, and HOIF₄O. When standing or when pumped to dryness, these mixtures decompose to yield NF₃ and the new compound FOIF₄O in high yield. The latter compound, the first known example of an iodine hypofluorite, was thoroughly characterized and shown by vibrational and NMR spectroscopy to be a mixture of the cis and trans isomers. For comparison, the vibrational spectra of IF₅O have also been recorded. The reaction of CsIF₄O₂ with ClOSO₂F was shown to yield the novel compound ClOIF₄O. The fluorination reactions of CsIO₄, CsIF₄O₂, IF₅O, and HOIF₄O with elementary fluorine were also studied.