Social Self‐Sorting of Ag₄ and Au₄ Alkynyl Complexes into Hetero–Tetranuclear Ag₂Au₂ Alkynyl Complexes: Ag₄ Alkynyl Complex as a Highly Reactive Silver Species

The designed alkynyl ligand 1 with a terphenyl framework reacts with Ag or Au salts to produce soluble tetranuclear Ag₄ and Au₄ alkynyl complexes 2 and 3 in high yields. In contrast, when ligand 1 is simultaneously reacted with both Ag and Au salts, the only formed product is the hetero-tetranuclear Ag₂Au₂ alkynyl complex 4, rather than complexes 2 and 3. Interestingly, when Ag₄ complex 2 is added to Au₄ complex 3 at room temperature, Ag₂Au₂ complex 4 is formed immediately and in quantitative yield. In contrast, the addition of Ag salts to Au₄ complex 3 results in incomplete or slow conversion. These findings suggest that Ag₄ complex 2 is more reactive than simple Ag salts and Au₄ complex 3 in the formation of Ag₂Au₂ complex 4. The high reactivity of Ag₄ complex 2 is further explored through ligand exchange experiments and gel permeation chromatography analyses.