Oxidative Rearrangement in Gold Organometallics

The one-electron oxidizing agent [NO]­PF<sub>6</sub> was reacted with Bu<sub>4</sub>N­[Au­(C<sub>6</sub>X<sub>5</sub>)<sub>2</sub>] (X = F, Cl) complexes in CH<sub>3</sub>CN. The gold­(III) complexes [Au­(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>(CH<sub>3</sub>CN)] and <i>cis</i>-[Au­(C<sub>6</sub>Cl<sub>5</sub>)<sub>2</sub>(CH<sub>3</sub>CN)<sub>2</sub>]­PF<sub>6</sub> 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(sp<sup>2</sup>)–F···H­(CH<sub>3</sub>CN) bond distance. The [Au­(C<sub>6</sub>Cl<sub>5</sub>)<sub>2</sub>(CH<sub>3</sub>CN)<sub>2</sub>]­PF<sub>6</sub> complex exhibits antisymbiosis, displaying equal ligands in the cis position. The electrochemical oxidation of Bu<sub>4</sub>N­[Au­(C<sub>6</sub>X<sub>5</sub>)<sub>2</sub>] (X = F, Cl) complexes in CH<sub>3</sub>CN 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.