Synthesis and characterisation of some new boron compounds containing the 2,4,6-(CF3)3C6H2 (fluoromes = Ar), 2,6-(CF3)2C6H3 (fluoroxyl = Ar′), or 2,4-(CF3)2C6H3 (Ar″) ligands

Abstract

Several new boron compounds containing the 2,4,6-(CF₃)₃C₆H₂ (fluoromes = Ar), 2,6-(CF₃)₂C₆H₃ (fluoroxyl = Ar′) or 2,4-(CF₃)₂C₆H₃ (Ar″) ligands have been synthesised from reactions of ArLi, Ar′Li or Ar″Li with BCl₃, and characterised by ¹⁹F and ¹¹B NMR spectroscopy. Chlorine/fluorine exchanges are evident in these reactions. The crystal and molecular structures of Ar₂BF, Ar″₃B, Ar₂B(OH), Ar′B(OH)₂ and Mes₂BF (Mes = 2,4,6-Me₃C₆H₂) have been determined by single crystal X-ray diffraction. Ar″₃B represents the first example of a compound containing three Ar″ ligands to be structurally characterised. Molecular geometries and GIAO-NMR shifts for several new boron compounds have been calculated at the HF/6-31G* level of theory, and compared with the available experimental results.