Social Self-Sorting of Ag4 and Au4 Alkynyl Complexes into Heterotetranuclear Ag2Au2 Alkynyl Complexes: Ag4 Alkynyl Complex as a Highly Reactive Silver Species.

Abstract

Our designed alkynyl ligand 1 with a terphenyl framework was reacted 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 was simultaneously reacted with both Ag and Au salts, the only formed product was the hetero-tetranuclear Ag2Au2 alkynyl complex 4, rather than complexes 2 and 3. Interestingly, when Ag4 complex 2 was added to Au4 complex 3 at room temperature, Ag2Au2 complex 4 formed immediately and in quantitative yield. On the other hand, the addition of Ag salts to Au4 complex 3 resulted 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 was further explored through ligand exchange experiments and GPC analyses.