title: Unraveling a generic growth pattern in structure evolution of thiolate-protected gold nanoclusters.
abstract: Precise control of the growth of thiolate-protected gold nanoclusters is a prerequisite for their applications in catalysis and bioengineering. Here, we bring to bear a new series of thiolate-protected nanoclusters with a unique growth pattern, i.e., Au20(SR)16, Au28(SR)20, Au36(SR)24, Au44(SR)28, and Au52(SR)32. These nanoclusters can be viewed as resulting from the stepwise addition of a common structural motif [Au8(SR)4]. The highly negative values of the nucleus-independent chemical shift (NICS) in the center of the tetrahedral Au4 units suggest that the overall stabilities of these clusters stem from the local stability of each tetrahedral Au4 unit. Generalization of this growth-pattern rule to large-sized nanoclusters allows us to identify the structures of three new thiolate-protected nanoclusters, namely, Au60(SR)36, Au68(SR)40, and Au76(SR)44. Remarkably, all three large-sized nanoclusters possess relatively large HOMO-LUMO gaps and negative NICS values, suggesting their high chemical stability. Further extension of the growth-pattern rule to the infinitely long nanowire limit results in a one-dimensional (1D) thiolate-protected gold nanowire (RS-AuNW) with a band gap of 0.78 eV. Such a unique growth-pattern rule offers a guide for precise synthesis of a new class of large-sized thiolate-protected gold nanoclusters or even RS-AuNW which, to our knowledge, has not been reported in the literature.
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China. gaoyi@sinap.ac.cn.
authors.forename: Wen Wu
authors.initials: WW
authors.lastname: Xu
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China. gaoyi@sinap.ac.cn and University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Li
authors.affiliation: Division of Interfacial Water and Key Laboratory of Interfacial Physics and Technology, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China. gaoyi@sinap.ac.cn and Shanghai Science Research Center, Chinese Academy of Sciences, Shanghai 201204, China and Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA. xzeng1@unl.edu.
authors.forename: Yi
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Department of Chemistry, University of Nebraska-Lincoln, Lincoln, NE 68588, USA. xzeng1@unl.edu and Collaborative Innovation Center of Chemistry for Energy Materials, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Xiao Cheng
authors.initials: XC
authors.lastname: Zeng