Fluoride crystal structures. Part XXIV. Tetrafluoroiodine(V)µ-fluoro-bis[pentafluoroantimonate(V)]

Abstract

Crystals of the title compound are monoclinic, space group P2₁/c, a= 8.52(1). b= 14.82(2), c= 9.98(1)Å, β= 112.7(3)°. The structure was solved by Patterson and Fourier methods and refined by three-dimensional least-squares methods to R0.089 for 1 299 reflections measured photographically. The atomic arrangement can be described by the ionic formulation [IF₄]⁺[Sb₂F₁₁]^–, but there is strong interionic fluorine bridging giving fluorine neighbours to the iodine at 2.51, 2.55, 2.83, and 2.94 Å, in addition to the four bonded atoms with mean I–F 1.80 Å.