Ligand Effects of Thiolate-Protected Au102 Nanoclusters

The Au 102 ( p -MBA) 44 ( p -MBA = para -mercaptobenzoic acid) nanocluster is an ideal model to study the structures of gold nanoclusters, the motifs of the monolayer ligand groups, and the crystal formation of Au nanoparticles. Based on the partially exchanged Au 102 ( p -MBA) 40 ( p -BBT) 4 ( p -BBT = para -bromobenzene thiol) crystal structure ( J. Am. Chem. Soc. 2012, 134, 13316–13322), we employed density functional theory to investigate the ligand effects for different thiolate substitutions. It was found that the intermolecular π–π stacking plays an important role for the crystal’s stability in addition to the increased intrinsic stability from the substituent monomer. Furthermore, we suggested para -(dimethylamino) benzenethiol (N(CH 3 ) 2 –C 6 H 4 –SH) and para -amino benzenethiol (NH 2 –C 6 H 4 –SH) would be more favorable than p -BBT for the stabilities of partially exchanged Au 102 ( p -MBA) 44 crystal structures due to their stronger intermolecular π–π stacking. This study provides a theoretical template for surface chemical engineering.