Toward Tunable Silver Superatoms. Evaluation of Electronic and Optical Properties of N-Heterocyclic Carbene [Ag ₁₃ Cl ₂ (L) ₅ ] ³⁺ Clusters

Versatile ultrasmall ligand-protected clusters appear as prototypical templates for evaluating a controllable variation at the bottom of the nanoscale range. Triggered by the recent finding of the phosphine-protected atomically precise Ag 13 core in [Ag 13 Cl 2 (dpppy) 5 ] 3+, we focus on the evaluation of the plausible incorporation of isolobal N-heterocyclic carbene ligands with the potential introduction of further versatility. Our results denote a [Ag 13 Cl 2 (NHC) 5 ] 3+ family with variable σ-donating capabilities according to the Tolman Electronic Parameter (TEP), unraveling the tunability of these 8- ce silver superatomic clusters. The ligand-dependent variations in HOMO–LUMO gaps and frontier orbital character, shifting from metal-core to a ligand-based LUMO, are desired for a controllable cluster electron injection to semiconductors. These findings reveal the potential for ligand-driven modulation of silver superatoms, advancing the design of cluster-based materials with tailored stability and functionality for molecular and electronic applications, as building blocks for nanostructured arrays.