An Au2S network model for exploring the structural origin, evolution, and two-electron (2e-) reduction growth mechanism of Aun(SR)m clusters.

An Au2S network model was proposed to study the structural origin, evolution, and formation mechanism of the Aun(SR)m clusters containing quasi-face-centered-cubic (fcc) cores. The Au–S framework structures of 20 quasi-fcc gold clusters had been determined from the Au2S network. Based on the Au2S network, some new quasi-fcc clusters, such as 8e− clusters Au24(SR)16, Au26(SR)18, Au26(SR)19−, Au29(SR)21, Au30(SR)22, and Au32(SR)24, and a class of Au24+8n(SR)20+4n (n = 1, 2, 3, …) clusters were predicted. Furthermore, by studying the evolution of Au–S frameworks, it was possible to construct molecular-like reaction equations to account for the formation mechanism of quasi-fcc gold clusters, which indicated that the formation of quasi-fcc gold clusters can be understood from the stepwise 2e−-reduction cluster growth pathways. The present studies showed that the Au2S network model provided a “parental” Au–S network for exploring the structural evolution of the quasi-fcc Aun(SR)m clusters. Moreover, it was possible to study the formation pathways of the Aun(SR)m clusters by studying the evolution of their Au–S frameworks.