(Fluoroorgano)fluoroboranes and ‐borates. 7 [1] The Reaction of RFBF2 and K [RFBF3] (RF = perfluorophenyl‐, perfluoroalk‐1‐enyl‐ and perfluoroalkyl) with Xenon Difluoride in Anhydrous HF

The dissolution of (perfluoroorgano)difluoroboranes R_FBF₂ in anhydrous HF (aHF) resulted in equilibrium mixtures of the starting borane and different kinds of acid‐base products: [H₂F] [R_FBF₂(F · HF)] (R_F = C₆F₅, cis‐C₂F₅CF=CF, trans‐C₄F₉CF=CF) or [H₂F] [R_FBF₃] (R_F = C₆F₁₃). In aHF the aryl compounds C₆F₅BF₂ and K [C₆F₅BF₃] showed two parallel reactivities with XeF₂: xenodeborylation (formation of the [C₆F₅Xe]⁺ cation) and fluorine addition to the aryl group. In aHF perfluoroalk‐1‐enyldifluoroboranes R_FBF₂ as well as potassium perfluoroalk‐1‐enyltrifluoroborates K [R_FBF₃] (R_F = cis‐C₂F₅CF=CF, trans‐C₄F₉CF=CF) underwent only fluorine addition across the carbon‐carbon double bond under the action of XeF₂. Potassium perfluorohexyltrifluoroborate K [C₆F₁₃BF₃] did not react with XeF₂ in aHF.