Zuo Dongjie, Guo Huifang, Xu Qinghua, He Ayisha, Li Zilin, Li Simin, Shen Hui
The College of Energy Materials and Chemistry, Inner Mongolia University, Hohhot 010021, China.
Nanoscale. 2024 Nov 7;16(43):20228-20234. doi: 10.1039/d4nr03320e.
N-Heterocyclic carbene (NHC) ligands have emerged as highly effective surface ligands for the protection and functionalization of metal nanoclusters (NCs). However, research on NHC-stabilized metal NCs, including their synthesis, structure, properties, and applications, is still in its early stages. In this study, we present the first gold-copper alloy cluster protected by both NHC and alkyne ligands, denoted as AuCu(NHC)(PA) (abbreviated as AuCu, where NHC is a bidentate N-heterocyclic carbene ligand with isopropyl as the N-substituent, and PA is a phenylethynyl group). The precise composition of AuCu was confirmed through the utilization of electrospray ionization mass spectrometry (ESI-MS), and its structure was determined X-ray single-crystal diffraction. It is worth noting that although the AuCu clusters do not display substantial light emission when exposed to UV lamps, they are capable of emitting green fluorescence subsequent to undergoing mechanical milling ( = 500 nm). Powder X-ray diffraction (PXRD) analysis reveals that this transition is attributed to a crystalline-amorphous transformation of the cluster crystals. These atomically precise alloy clusters are expected to serve as a model for further investigation into the principles of mechanical milling of metal clusters for discolouration.
N-杂环卡宾（NHC）配体已成为用于金属纳米团簇（NCs）保护和功能化的高效表面配体。然而，关于NHC稳定的金属纳米团簇的研究，包括其合成、结构、性质和应用，仍处于早期阶段。在本研究中，我们展示了首个同时由NHC和炔烃配体保护的金铜合金团簇，记为AuCu(NHC)(PA)（简称为AuCu，其中NHC是一种以异丙基为N取代基的双齿N-杂环卡宾配体，PA是苯乙炔基）。通过电喷雾电离质谱（ESI-MS）确定了AuCu的精确组成，并通过X射线单晶衍射确定了其结构。值得注意的是，尽管AuCu团簇在紫外灯下不显示大量发光，但在进行机械研磨后（λ = 500 nm）它们能够发出绿色荧光。粉末X射线衍射（PXRD）分析表明，这种转变归因于团簇晶体的晶态-非晶态转变。这些原子精确的合金团簇有望作为进一步研究金属团簇机械研磨致变色原理的模型。
