Alkynyl ligand for preparing atomically precise metal nanoclusters: Structure enrichment, property regulation, and functionality enhancement

Ligand plays a critical role in determining the physicochemical properties and functionalities of metal nanoclusters, as the ligand molecules interact with a significant amount of metal atoms in the core through various binding moieties. Compared with the most commonly employed thiolate molecule, alkynyl ligand represents a new avenue to prepare coinage metal nanoclusters due to its capability of binding to the metal atoms with either σ bonding or π bonding or both. In this review, we first describe the definition of atomically precise metal nanoclusters and the significance of ligand in metal nanoclusters. Then, the impact and unique advantages of employing alkynyl ligand for fabricating coinage metal nanoclusters are discussed, with focus on the enrichment of interfacial binding structure, the regulation of physicochemical properties, and the improvement of functionalities. Some explicit examples are provided, aiming to elucidate the structure-property-functionality relationship at the atomic level. Finally, a conclusion and introspective outlook regarding designing alkynyl ligand for future regulation of the structure/property/functionality of metal nanoclusters is presented.