Thermal Stability and Electronic Properties of N-Heterocyclic Carbene-Protected Au 13 Nanocluster and Phosphine-Protected Analogues.

Despite significant advances in manufacturing atomically precise gold nanoclusters protected by various ligands, there is a limited understanding of the thermal stability dynamics and electronic properties of ligand effects. We conducted ab initio molecular dynamics (AIMD) simulations on the well-characterized [Au 13 (NHC Me ) 9 Cl 3 ] 2+ nanocluster and its counterpart [Au 13 (PMe 3 ) 9 Cl 3 ] 2+ cluster to evaluate the thermal stability induced by N-heterocyclic carbene (NHC) and phosphine ligands. The result shows that under vacuum conditions, [Au 13 (PMe 3 ) 9 Cl 3 ] 2+ is more stable than [Au 13 (NHC Me ) 9 Cl 3 ] 2+ , and both lead to metal nucleation decomposition, breaking into the Au 12 fragment and L-Au-Cl (L = NHC Me or PMe 3 ) complexes eventually. The optical and electronic properties of these two clusters change significantly due to ligand alteration. Furthermore, we have designed a novel [Au 13 (NHC Me )(PMe 3 ) 8 Cl 3 ] 2+ cluster coprotected by NHC and phosphine ligands, displaying higher thermal stability than the homoligand protected [Au 13 (NHC Me ) 9 Cl 3 ] 2+ and [Au 13 (PMe 3 ) 9 Cl 3 ] 2+ . Our hypothetical species are an interesting model for nanostructured materials, facilitating the experimental exploration of cluster synthesis and catalytic applications.