Understanding the interaction between carboxylates and coinage metals from first principles

Area of Science:

• Surface Science
• Computational Chemistry
• Materials Science

Background:

• Carboxylate groups are emerging ligands for protecting superatomic copper and silver nanoclusters.
• Understanding the interfacial structure and bonding of these ligands is crucial but limited.

Purpose of the Study:

• To investigate the interfacial structure and bonding of carboxylate groups on coinage metal surfaces and clusters using computational methods.
• To explore the preferred binding modes and stability of carboxylate ligands on Cu, Ag, and Au surfaces and M13 clusters.

Main Methods:

• Density functional theory (DFT) calculations were employed.
• Investigated model carboxylate (CH3COO) interactions on M(111) surfaces (M = Cu, Ag, Au) and icosahedral M13 clusters.

Main Results:

• The μ2-CH3COO binding mode is preferred on M(111) surfaces, with μ3-CH3COO also stable on Cu(111) and Ag(111).
• Saturation coverage is approximately seven CH3COO groups/nm², with strongest binding on Cu and weakest on Au.
• Superatomic [M13(CH3COO)6]− nanoclusters also favor the μ2-CH3COO mode, maintaining cluster integrity for Cu and Ag but showing deformation for Au.

Conclusions:

• Carboxylate groups, particularly the μ2 binding mode, are effective ligands for coinage metal surfaces and nanoclusters.
• The findings suggest carboxylate groups are promising next-generation ligands for expanding the diversity of atomically precise metal clusters, especially for copper and silver.