Arylation of gold nanoclusters and insights into structure-related CO2 reduction reaction performances.

Research on arylgold complexes and ligand-protected gold nanoclusters has proceeded independently thus far due to the difficulty in controllably introducing aryl groups to synthesize arylgold nanoclusters. Herein we synthesized an arylgold Au15 nanocluster, Au15(DPPOE)3(S-Ph p Me)4(Ph)2, thereby bridging the two independent research fields. Tetraarylborates were exploited as arylating agents to transfer aryl groups onto the nanocluster kernel, triggering the arylation of the Au15 cluster while maintaining the molecular framework. Furthermore, two other arylgold Au15 nanoclusters with halogenated surfaces were controllably synthesized by substituting the arylating agent NaBPh4 with its benzene ring-halide derivatives. In addition, the change in the electronic structure from Au-SR to Au-aryl and the energetics of the arylation process from Au15-SR to Au15-Ph were elucidated computationally. Furthermore, the catalytic capability of the two Au15 nanoclusters with nuanced ligand differences was investigated in the electrochemical reduction of CO2, and the comparable reactivity of the two cluster-based nanocatalysts was theoretically rationalized. Our findings have cross-fertilized the fields of arylgold complexes and gold nanoclusters, pointing toward a new avenue of exploration for novel arylgold nanoclusters.