Precise Surface Engineering of Metal Nanoclusters: Ligand Programming for Functionality Design

Precise surface engineering of metal nanoclusters (MNCs) has emerged as a powerful strategy for tailoring their structural, electronic, and catalytic properties. On the basis of traditional surface chemistry, ligand programming enables atomic-level control over MNC functionality by modulating metal-ligand coordination, intra/inter-ligand interactions, and interfacial chemistry. These three layers within the "Engineering Zone" define structural flexibility, charge transfer pathways, molecular rigidity, and surface accessibility, key factors in optimizing catalytic activity, luminescence efficiency, and molecular recognition. This Perspective explores the chemistry governing ligand-directed MNC behavior in the three layers, highlighting its role in catalysis, photonics, and biomedicine. By integrating coordination chemistry, intra/inter-ligand design, and interfacial interactions, how ligand programming transforms MNCs is demonstrated into tunable platforms for next-generation functional materials. Insights from MNCs also provide a model for advancing surface engineering in broader nanomaterials, paving the way for innovative applications in materials science.