Syntheses and luminescence studies of mixed-metal gold(I)–copper(I) and –silver(I) alkynyl complexes. The turning-on of emission upon d10 metal ion encapsulation

Reaction of the gold(I) alkynyl precursor complexes, [(R3P)Au{CCC(CH2)Me}](R = Ph 1, p-Tol 2) and [(mu-dppf)Au2{CCC(CH2)Me}2]3, with copper(I) or silver(I) ions led to the formation of a series of luminescent 2-alkynyl mixed-metal complexes, [{2- (R3P)Au{eta2-CequivqlentCC-(CH2)Me}}2Cu]PF6(R = Ph 4, p-Tol 5) and [(mu-dppf)Au2{2-CCC(CH2)Me}2M]X (M = Cu, X = PF66; M = Ag, X = OTf 7). The X-ray crystal structures of 1 and 3 have been determined. The photophysical properties of the complexes have been investigated. Coordination of 1–3 as metalloligands to copper(I) and silver(I) ions to afford the respective complexes 4–7 has been demonstrated to be a versatile means to perturb the emission properties. The luminescence behaviour of 3 has been turned on upon copper(I) or silver(I) encapsulation in 6 and 7.