Oxidative Rearrangement in Gold Organometallics

The one-electron oxidizing agent [NO]­PF₆ was reacted with Bu₄N­[Au­(C₆X₅)₂] (X = F, Cl) complexes in CH₃CN. The gold­(III) complexes [Au­(C₆F₅)₃(CH₃CN)] and cis-[Au­(C₆Cl₅)₂(CH₃CN)₂]­PF₆ were synthesized by the oxidation of gold­(I) to gold­(III) with the concomitant ligand rearrangement “oxidative rearrangement”. The supramolecular crystal packing in the perfluorinated aryl gold­(III) complex is dictated by the notably short C­(sp²)–F···H­(CH₃CN) bond distance. The [Au­(C₆Cl₅)₂(CH₃CN)₂]­PF₆ complex exhibits antisymbiosis, displaying equal ligands in the cis position. The electrochemical oxidation of Bu₄N­[Au­(C₆X₅)₂] (X = F, Cl) complexes in CH₃CN showed two irreversible peaks at 0.71 and 1.21 V (X = F) and at 0.65 and 0.91 V (X = Cl) vs Ag/AgCl.