Metal-metal bond formation in the oxidative addition to dinuclear gold(I) species. Implications from dinuclear and trinuclear gold chemistry for the oxidative addition process generally

The oxidation or attempted oxidation by small-molecule oxidants of the linear [Au ⋯ Pt ⋯ Au], [Au ⋯ Pb ⋯ Au] and [Hg ⋯ Pt ⋯ Hg]2+ require us to acknowledge that neighbouring-atom electronic features can both inhibit and promote the oxidative addition process. A similar type of electronic influence appears prevalent in the oxidative addition to dinuclear AuI complexes and probably exists whenever the Goddard-Low concept of oxidative addition can involve both metal atoms in the process. Metal-metal bond formation accompanying the oxidative addition stabilizes intermediates which lead to the formation of products in which the addend adds across the metal-metal bond(s). The promotion of the oxidative addition will depend on the case of closed-shell to open-shell promotion of the neighbouring atom as well as the atom to which the adduct initially interacts. Such behaviour presumably exists in many systems wherein bimetallic heterogeneous catalysis is more effective than in the monometallic system.