Highly luminescent gold (I)-silver(I) and gold(I)-copper(I) chalcogenide clusters

The reactions of [AuCIL] with Ag2O, where L represents the heterofunctional ligands PPh2Py and PPh(2)CH(2)CH(2)py, give the trigoldoxonium complexes [O(AuL)(3)]BF4. Treatment of these compounds with thio- or selenourea affords the triply bridging sulfide or selenide derivatives [E(AuL)(3)]BF4 (E = S, Se). These trinuclear species react with Ag(OTf) or [Cu(NCMe)(4)]PF6 to give different results, depending on the phosphine and the metal. The reactions of [E(AuPPh(2)py)(3)]BF4 with silver or copper salts give [E(AuPPh(2)py)(3)M](2+) (E = O, S, Se; M = Ag, Cu) clusters that are highly luminescent. The silver complexes consist of tetrahedral Au3Ag clusters further bonded to another unit through aurophilic interactions, whereas in the copper species two coordination isomers with different metallophilic interactions were found. The first is analogous to the silver complexes and in the second, two [S(AuPPh(2)py)(3)](+) units bridge two copper atoms through one pyridine group in each unit. The reactions of [E(AuPPh(2)CH(2)CH(2)py)(3)]- BF4 with silver and copper salts give complexes with [E(AuPPh(2)CH(2)CH(2)py)(3)M](2+) stoichiometry (E = O, S, Se; M = Ag, Cu) with the metal bonded to the three nitrogen atoms in the absence of An(...)M interactions. The luminescence of these clusters has been studied by varying the chalcogenide, the heterofunctional ligand, and the metal.