Solvent-triggered reversible interconversion of all-nitrogen-donor-protected silver nanoclusters and their responsive optical properties

Shang-Fu Yuan,Quan-Ming Wang,Wen-Di Liu,Zong-Jie Guan

doi:10.1038/s41467-019-11988-y

Shang-Fu Yuan, Quan-Ming Wang + Show 2 more

Open Access

https://doi.org/10.1038/s41467-019-11988-y

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Journal: Nature Communications	Publication Date: Sep 6, 2019
Citations: 87	License type: open-access

Affiliation: Xiamen University, Tsinghua University

Abstract

Surface organic ligands are critical in determining the formation and properties of atomically precise metal nanoclusters. In contrast to the conventionally used thiolate, phosphine and alkynyl ligands, the amine ligand dipyridylamine is applied here as a protecting agent in the synthesis of atomically precise metal nanoclusters. We report two homoleptic amido-protected Ag nanoclusters as examples of all-nitrogen-donor-protected metal nanoclusters: [Ag21(dpa)12]SbF6 (Ag21) and [Ag22(dpa)12](SbF6)2 (Ag22) (dpa = dipyridylamido). Single crystal X-ray structural analysis reveals that both clusters consist of a centered-icosahedron Ag13 core wrapped by 12 dpa ligands. The flexible arrangement of the N donors in dpa facilitates the solvent-triggered reversible interconversion between Ag21 and Ag22 due to their very different solubility. The successful use of dpa in the synthesis of well-defined silver nanoclusters may motivate more studies on metal nanoclusters protected by amido type ligands.

Highlights

Surface organic ligands are critical in determining the formation and properties of atomically precise metal nanoclusters
In order to isolate a stable amido-protected metal nanocluster, which is helpful for making structural determination possible, our strategy is to use dipyridylamine (Hdpa) as a multidentate protecting agent
Hdpa turns into a monoanionic dipyridylamido ligand, which contains one amido and two pyridyl N donors available for bridging multi metal centers

Summary

Introduction

Surface organic ligands are critical in determining the formation and properties of atomically precise metal nanoclusters. Both clusters have very similar structures based on a centered-icosahedral Ag13 core, with different number of shell silver atoms ligated by the same number of homoleptic dpa ligands. A rapid reduction without MeONa gave a red solution that showed a broad plasmonic resonance absorption peak at ~450 nm, which indicates the formation of nanoparticles instead of clusters (Supplementary Fig. 3).

Results

Conclusion