Construction of Silver Clusters Capped by Zwitterionic Ethynide Ligands.

Area of Science:

• Inorganic Chemistry
• Materials Science
• Coordination Chemistry

Background:

• Silver ethynide compounds are of interest due to their unique structures and potential applications.
• The synthesis of complex silver clusters often requires careful selection of ligands to control nuclearity and architecture.

Purpose of the Study:

• To synthesize and characterize novel silver ethynide compounds using a zwitterionic ligand.
• To explore the influence of auxiliary ligands on the formation of silver ethynide clusters.
• To investigate the structural diversity of silver ethynide assemblies, from small subunits to large clusters.

Main Methods:

• Single-crystal X-ray diffraction analysis was used to determine the structures of the synthesized compounds.
• Thermogravimetric analysis was employed to characterize the thermal stability and composition of the large silver cluster.
• The use of 3-(triethylammonio)propyne (TAP) as a zwitterionic ligand was central to the synthetic strategy.

Main Results:

• Nine new silver ethynide compounds were synthesized, including assemblies based on Ag3 subunits and discrete clusters of Ag3, Ag6, Ag8, and Ag12.
• An unprecedented 80-nucleus silver ethynide cluster, [(CF3CO2)5@Ag80(TAP)14(tBuPO3)16(CF3CO2)24]19+, was isolated and structurally characterized.
• The Ag80 cluster features a unique cross-shaped arrangement of two Ag40 subunits, with trapped trifluoroacetate anions.
• The bulky TAP ligand played a crucial role in ligating the silver atoms and influencing cluster formation.

Conclusions:

• The choice of ethynide ligand is critical for the successful synthesis of novel and complex silver ethynide clusters.
• The use of zwitterionic ligands like TAP can lead to the formation of diverse silver ethynide architectures.
• The discovery of the large Ag80 cluster opens new avenues for exploring the synthesis of polynuclear silver compounds.