Ligand Effects on Luminescence of Atomically Precise Gold Nanoclusters
Wan-Qi Shi, Linlin Zeng, Zhen-Chao Long, Zong‐Jie Guan, Xu‐Shuang Han, Feng Hu, Meng Zhou, Quan‐Ming Wang
Abstract
Great efforts have been made to establish the structure–property relationships of ligand-protected metal nanoclusters. An alkynyl-protected gold nanocluster Au 28 ( t BuC 6 H 4 C≡C) 20 ( Au 28 -C 2 ) was synthesized and structurally characterized. It has an isostructural metal kernel and a quite similar ligand shell to its counterpart Au 28 ( t BuC 6 H 4 S) 20 ( Au 28 -S ), which provides a valuable platform for studying ligand effects on the luminescence of clusters. The emission intensity of Au 28 -C 2 in solution is ∼10-fold that of Au 28 -S . The only structural difference between these two clusters is the donor atom or group, i.e., C≡C for Au 28 -C 2 versus S for Au 28 -S . Temperature-dependent experiments indicate that the two Au 28 clusters have different thermodynamic behaviors and radiative processes. The study on the excited-state dynamics by transient absorption spectroscopy indicates that Au 28 -C 2 has a larger triplet-state population than Au 28 -S . This work shows important ligand effects on the emission properties of metal nanoclusters, which provide new perspectives for the designed synthesis of functional metal nanoclusters.