Silver(I) Double and Multiple Salts Containing the 1,3‐Butadiynediide Dianion: Coordination Diversity and Assembly with the Supramolecular Synthon Ag4⊂CC?CC⊃Ag4

A series of 13 silver(I) double and multiple salts containing 1,3‐butadiynediide, C₄^2?, were synthesized by dissolving the silver carbide Ag₂C₄ in a concentrated aqueous solution of one or more of the silver salts AgNO₃, AgCF₃CO₂, AgC₂F₅CO₂, AgF, AgBF₄, and AgPF₆. The 1,3‐butadiynediide anion invariably adopts a μ₄,μ₄ coordination mode in these compounds, which indicates that the Ag₄?C?C? C?C?Ag₄ moiety can be used as a new type of metalloligand supramolecular synthon for the construction of coordination networks. Fine‐tuning with various ancillary anionic ligands caused the Ag₄ aggregate at each ethynide terminus to adopt a butterfly‐shaped, planar, or barblike configuration, within which the silver–ethynide interactions can be classified into three types: σ, π, and mixed (σ,π). The effect of coexisting nitrile ligands and quaternary ammonium salts on supramolecular assembly with the above synthon was also explored. The hydrolysis of PF₆^? and BF₄^? led to the formation of the quadruple salt Ag₂C₄?4 AgNO₃?AgPF₂O₂?Ag₃PO₄ and a novel (F)₂(H₂O)₁₈ hydrogen‐bonded tape in the triple salt Ag₂C₄?2 AgF? 10 AgC₂F₅CO₂?CH₃CN?12 H₂O, respectively. The largest silver–ethynide cluster aggregate described to date, (C₄)₃@Ag₁₈, occurs in 3 Ag₂C₄? 12 AgC₂F₅CO₂?5(BnMe₃N)C₂F₅CO₂]? 4 H₂O (Bn=benzyl).