Trinuclear Mixed-valent Gold Complexes Derived from 2-C6F4PPh2: Phosphine Oxide Complexes of Gold(III) and an ortho-Metallated Complex of Gold(I)

Abstract

Crystals of two mixed-valent gold complexes [(O2NO)AuI(μ-2-C6F4PPh2)AuIII{κ2-2-C6- F4P(O)Ph2}(μ-2-C6F4PPh2)AuI(ONO2)] (14) and [(O2NO)AuI(μ-2-C6F4PPh2)AuIII{κ3-2-C6F4- P(O)Ph(C6H4)}(μ-2-C6F4PPh2)AuI] (15) have been obtained from the reaction of the digold(I,III) complex [ClAuI(μ-2-C6F4PPh2)(κ2-2-C6F4PPh2)AuIIICl] (5) with, respectively, a small and a large excess of silver nitrate. Both complexes contain three, approximately collinear metal atoms, the central gold(III) atom being planar-coordinated by a chelate (O,C)-phosphine oxide formed by oxidation of 2-C6F4PPh2 and the carbon atoms of two bridging 2-C6F4PPh2 groups. In 14 each of the terminal gold(I) atoms is coordinated by a monodentate nitrate ion and the phosphorus atom of μ-2-C6F4PPh2, whereas in 15 the nitrate ion on one of the gold(I) atoms of 14 has been replaced by the carbon atom of a bridging C6H4 group derived by Ag+-promoted cyclometallation of a phenyl group on the neighbouring phosphine oxide