Dinuclear Au(I), Au(II) and Au(III) Complexes with (CF2)n Chains: Insights into The Role of Aurophilic Interactions in the Au(I) Oxidation

Abstract

New dinuclear Au(I), Au(II) and Au(III) complexes containing (CF 2 ) n bridging chains were obtained. Metallomacrocycles [Au 2 {μ-(CF 2 ) 4 }{μ-diphosphine}] show an uncommon figure-eight structure, whose helicity inversion barrier is influenced by aurophilic interactions and steric constraints imposed by the diphosphine. Halogenation of LAu(CF 2 ) 4 AuL (L = PPh 3 , PMe 3 , (dppf) 1/2 , (binap) 1/2 ) gave [Au(II)] 2 species, some of which display unprecedented folded structures with Au–Au bonds. Aurophilic interactions facilitate this oxidation process by preorganizing the starting [Au(I)] 2 complexes and lowering its redox potential. The obtained [Au(II)] 2 complexes undergo thermal or photochemical elimination of R 3 PAuX to give Au(III) perfluorinated auracycles. Evidence of a radical mechanism for these decomposition reactions was obtained.