Assembly of silver(<sc>i</sc>)-copper(<sc>i</sc>) bimetallic thiolate complexes assisted by phenylacetylene stabilizers

AgI/CuI bimetallic clusters have been widely reported, but synthesis of such clusters via simple self-assembly of heterometallic ions in air remains challenging due to the susceptibility of CuI ions to oxidation. In this study, protected by the phenylacetylene auxiliary ligand, we utilized [Cu(CH3CN)4]PF6 in conjunction with the (iPrSAg)n polymer to form Ag(i)-Cu(i) oligomer precursors, serving as the starting point for constructing a new [Ag11-xCux(iPrS)9(DPPM)3](PF6)2 cluster (DPPM = bis(diphenylphosphino)methane, Ag11-xCux, x = 5-9). When the (iPrSAg)n precursor was replaced by (tBuSAg)n, another cluster [Ag21Cu4S2(tBuS)18(CH3CN)4](CH3OH)2(H3O)(PF6)4 (Ag21Cu4) was obtained. By combining crystallographic data and electrospray ionization mass spectrometry (ESI-MS) results, the compositions and structures of these two new clusters were determined. Additionally, the optical physical properties of the luminescent Ag11-xCux were investigated, showing red phosphorescence emission in both solid-state and solution phases. The solid-state phosphorescence quantum yield (QY) is 8%, with a lifetime of 7.2 mu s. These findings suggest that phenylacetylene auxiliary ligands can effectively stabilize CuI ions and guide the assembly of silver-copper bimetallic thiolate motifs into new compounds under ambient conditions.