Reactivity of an acetylenephosphino gold(III) precursor:: Addition to the triple bond or formation of alkynyl derivatives

We have synthesized the gold(III) complex Au(C6F5)(3)(PPh2CCH) (1), containing an acetylene moiety. Reactions with sodium alkoxides lead chemoselectively and regioselectively to gold(III) complexes containing the new ligand (2-alkoxyethenyl)diphenylphosphine or (2,2-dialkoxyethyl)diphenylphosphine, via a single or double alcohol addition to the acetylenephosphine fragment. Reaction of complex I with gold(I) or silver(I) acetylacetonato derivatives affords di-, tri-, or tetranuclear alkynyl-phosphino complexes, namely Au-III(C6F5)(3)(PPh2CC)-M-I(PPh3) (M = Au, Ag), {Au-III(C6F5)(3)(PPh2CC)}(2)Au-I, and {Au-III(C6F5)(3)(PPh2CC)Au-I}(2)(mu -PPh2CH2CH2PPh2). The crystal structures of Au(C6F5)(3)(PPh2CH2CH(OMe)(2)) and Au-III(C6F5)(3)(PPh2CC)Au-I(PPh3) have been determined by X-ray diffraction studies. Luminescence studies in the solid state show that only the tetranuclear derivative is luminescent at room temperature.