Is the kernel-staples match a key-lock match?

Shengli Zhuang,Zhikun Wu,Lingwen Liao,Jin Li,Jinyun Yuan,Xu Liu,Chuanhao Yao,Yan Zhao,Jinlong Yang,Haiteng Deng

doi:10.1039/c7sc05019d

Abstract

Metal nanoclusters provide excellent references for understanding metal nanoparticle surfaces, which remain mysterious due to the difficulty of atomically precise characterization. Although some remarkable advances have been achieved for understanding the structure of metal nanoclusters, it is still unknown if the inner kernel-outer staples match is a key-lock match and how the surface staples influence some of the properties of metal nanoclusters. Herein, we have developed an acid-induction method for synthesizing a novel gold nanocluster whose composition is determined to be Au42(TBBT)26 (TBBT: 4-tert-butylbenzenelthiolate) by ESI-MS and single-crystal X-ray crystallography (SCXC). SCXC also reveals that Au42(TBBT)26 has an identical kernel but different staples with an existing gold nanocluster Au44(TBBT)28, indicating that the kernel-staples match is not a key-lock match and the existence of homo-ligand-homo-kernel-hetero-staples phenomenon in metal nanoclusters provides some reference for understanding the growth or transformation of metal nanoclusters. Further experiments reveal that the staples greatly contribute to the stability of gold nanoclusters and influence their photoluminescence intensity and that minute differences in the interfacial structure can lead to enhanced stability and photoluminescence.

Highlights

Ligand-protected metal nanoparticles have received extensive interest for fundamental scienti c research and for their practical applications over the past several decades.[1]
The synthesis of Au42(TBBT)[26] nanoclusters was according to the method described by us in our previous study.3v Some modi cations were made to this method, and the details are provided in the experimental section
Based on the above discussion, Au42(TBBT)[26] has an identical Au34 kernel but different staples, which indicates that the kernel–staples match is not a key–lock match and that the homo-ligand–homo-kernel–hetero-staples phenomenon exists in metal nanoclusters, which has not been previously reported to the best of our knowledge

Summary

Introduction

Ligand-protected metal nanoparticles have received extensive interest for fundamental scienti c research and for their practical applications over the past several decades.[1]. These questions are important to understand the interaction between staples and the kernel, the staples' in uence on the properties, and the growth (or transformation) mechanism of metal nanoclusters.[6] To address these questions, we have developed a method to synthesize a novel gold nanocluster protected by 4-tert-butylbenzenelthiolate (TBBT), which has identical Au34 kernels but varied staples with an existing gold nanocluster-Au44(TBBT)[28], and we compare the stability and photoluminescence properties between the two homo-kernelled gold nanoclusters.

Results

Conclusion