Luminescent Silver–Copper “Hourglass” Hepta‐ and Decanuclear Alkynyl‐Phosphine Clusters

Abstract

The heterometallic Ag–Cu compounds easily assemble from the corresponding metal triflates and alkynes in the presence of tris(diphenylphosphanyl)methane (tppm) under basic conditions. The formation of two types of cluster skeletons – heptanuclear [Ag6Cu(C2R)3{HC(PPh2)3}2(CF3SO3)3](CF3SO3) {R = C6H4‐4‐X (X = CF3, 1A; OMe, 2A; NMe2, 3A; NC10H20O4, 4A); CPh2OH, 5A} and decanuclear [Ag6Cu4(C2C6H4‐4‐X)8{HC(PPh2)3}2](CF3SO3)2 (X = CF3, 1B; H, 6B) species is governed by the electronic properties of the alkynyl ligands and the ratio of the starting components. All of the complexes, except 4A, were structurally characterized by single‐crystal XRD analysis. The solid‐state photophysical studies reveal room‐temperature phosphorescence (Φem = 0.3–42.5 %, λem = 556–756 nm), which is dependent on the electron‐donating ability of the alkynyl fragments and the nature of the metal core. Moreover, the geometry of the cluster framework is substantially influenced by the bridging counterions that, together with electronic modulation of organic blocks, allow near‐IR emission.