Controlled reduction for size selective synthesis of thiolate-protected gold nanoclusters Aun(n = 20, 24, 39, 40)

Xiangming Meng,Zhao Liu,Rongchao Jin,Manzhou Zhu

doi:10.1186/1556-276x-7-277

Xiangming Meng, Zhao Liu + Show 2 more

Open Access

PDF Available

https://doi.org/10.1186/1556-276x-7-277

Copy DOI

Export

Save

Cite

Abstract
Highlights/Summary
Full-Text PDF
Similar Papers

Abstract

Listen

This work presents a controlled reduction method for the selective synthesis of different sized gold nanoclusters protected by thiolate (SR = SC2H4Ph). Starting with Au(III) salt, all the syntheses of Aun(SR)m nanoclusters with (n, m) = (20, 16), (24, 20), (39, 29), and (40, 30) necessitate experimental conditions of slow stirring and slow reduction of Au(I) intermediate species. By controlling the reaction kinetics for the reduction of Au(I) into clusters by NaBH4, different sized gold nanoclusters are selectively obtained. Two factors are identified to be important for the selective growth of Au20, Au24, and Au39/40 nanoclusters, including the stirring speed of the Au(I) solution and the NaBH4 addition speed during the step of Au(I) reduction to clusters. When comparing with the synthesis of Au25(SC2H4Ph)18 nanoclusters, we further identified that the reduction degree of Au(I) by NaBH4 also plays an important role in controlling cluster size. Overall, our results demonstrate the feasibility of attaining new sizes of gold nanoclusters via a controlled reduction route.

Highlights

Identification of Au39(SC2H4Ph)29 and Au40(SC2H4Ph)30 Starting with an Au(III) salt precursor, the synthesis of gold nanoclusters involves two primary stages: (a) reduction of Au(III) to Au(I) by HSR, during which the formed Au(I) intermediate species spontaneously aggregates into polymeric Au(I) species, and (b) reduction of Au(I) to Aun(SR)m nanoclusters by sodium borohydride (NaBH4)
To synthesize larger-sized nanoclusters, we rationalize that the kinetics of the reduction reaction of Au(I) intermediate species by NaBH4 may be important for potential size control
This work has demonstrated the effectiveness of controlled reduction for synthesizing different sized gold nanoclusters

Summary

Introduction

Gold nanoclusters [1,2,3,4,5,6] have received extensive attention owing to their interesting optical properties [6,7,8,9], magnetism [10,11], fluorescence [12,13,14,15,16], chirality [17,18,19,20], redox properties [21,22,23,24,25,26,27], as well as potential applications in many fields such as catalysis and biological labeling [28,29,30,31,32,33]. Other well-defined nanoclusters have been attained, such as Au36 [42], Au38 [43,44], Au102 [45], and Au144 [46,47]

Methods

Results

Conclusion