Gold(III) derivatives with anionic oxygen ligands: mononuclear hydroxo, alkoxo and acetato complexes. Crystal structure of [Au(bpy)(OMe)2][PF6]

Abstract

A variety of gold(III) adducts having σ-ligated oxygen-donor ligands have been prepared from [Au(bpy)Cl₂][PF₆] 1 (bpy = 2,2′-bipyridine) either by partial or total replacement of the chloride ions. The new species comprise hydroxo, [Au(bpy)(OH)Cl][PF₆] 2 and [Au(bpy)(OH)₂][PF₆] 3, oxo, [Au₂(bpy)₂(μ-O)₂][PF₆]₂4, acetato, [Au(bpy)(O₂CMe)₂][PF₆] 5, and alkoxo complexes, [Au(bpy)(OR)Cl][PF₆] 6, 7 and [Au(bpy)(OR)₂][PF₆] 8–10 (R = Me 6 and 8; Et 7 and 9; Prⁱ10). The dihydroxo and the oxo complexes can be interconverted by refluxing the former in anhydrous THF and the latter in water. The hydroxides 2 and 3 and the acetato complex 5 undergo σ-ligand metathesis in ROH solution (R = Me, Et or Prⁱ) to give the corresponding alkoxides. The crystal structure of 8, the first of a gold(III) methoxo complex, has been determined by X-ray diffraction analysis.