Deng Guocheng, Malola Sami, Ki Taeyoung, Liu Xiaolin, Yoo Seungwoo, Lee Kangjae, Bootharaju Megalamane S, Häkkinen Hannu, Hyeon Taeghwan
Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 08826, Republic of Korea.
School of Chemical and Biological Engineering, and Institute of Chemical Processes, Seoul National University, Seoul 08826, Republic of Korea.
J Am Chem Soc. 2024 Oct 2;146(39):26751-26758. doi: 10.1021/jacs.4c06832. Epub 2024 Sep 18.
Structural isomers of atomically precise metal nanoclusters are highly sought after for investigating structure-property relationships in nanostructured materials. However, they are extremely rare, particularly those of alloys, primarily due to the challenges in their synthesis and structural characterization. Herein, for the first time, a pair of bimetallic isomeric AgCu nanoclusters has been controllably synthesized and structurally characterized. These two isomers share an identical molecular formula, AgCu(C≡CR) (denoted as and ; HC≡CR is 3,5-bis(trifluoromethyl)phenylacetylene). Single-crystal X-ray diffraction data analysis revealed that possesses an AgCu core composed of two interpenetrating hollow AgCu structures. This core is stabilized by four different types of surface motifs: eight -C≡CR, one Cu(C≡CR), one AgCu(C≡CR), and two Cu(C≡CR) units. features a bitetrahedron Ag core, which is stabilized by three AgCu(C≡CR) units. Interestingly, undergoes spontaneous transformation to in the solution-state. Density functional theory calculations explain the electronic and optical properties and confirm the higher relative stability of compared to . The controlled synthesis and structural isomerism of alloy nanoclusters presented in this work will stimulate and broaden research on nanoscale isomerism.
原子精确的金属纳米团簇的结构异构体在研究纳米结构材料的结构-性质关系方面备受追捧。然而，它们极为罕见，尤其是合金的结构异构体，主要是因为其合成和结构表征面临挑战。在此，首次可控地合成并对一对双金属异构AgCu纳米团簇进行了结构表征。这两种异构体具有相同的分子式AgCu(C≡CR)（分别记为 和 ；HC≡CR为3,5-双（三氟甲基）苯乙炔）。单晶X射线衍射数据分析表明， 具有由两个相互贯穿的中空AgCu结构组成的AgCu核。该核由四种不同类型的表面基序稳定：八个 -C≡CR、一个Cu(C≡CR)、一个AgCu(C≡CR)和两个Cu(C≡CR)单元。 具有一个双四面体Ag核，由三个AgCu(C≡CR)单元稳定。有趣的是， 在溶液状态下会自发转变为 。密度泛函理论计算解释了其电子和光学性质，并证实 相对于 具有更高的相对稳定性。这项工作中展示的合金纳米团簇的可控合成和结构异构性将激发并拓宽对纳米级异构现象的研究。
