新加坡国立大学Xie Jianping团队报道了表面动力学促进原子精确金纳米颗粒的超晶体工程。相关研究成果发表在2022年11月10日出版的《自然—化学》。

功能纳米颗粒（NPs）在晶格中的可控填充在NP基材料的开发中具有重要意义。

该文中，研究人员证明了这种超晶体的尺寸、形态和对称性可以通过调整其组成NPs的表面动力学来调整。在过量的四乙基铵阳离子存在下，原子精确的[Au25(SR)18] NP（其中SR是硫代酸盐配体）可以结晶成微米大小的六方棒状超晶体，而不是面心立方超晶格。

理论模型支持的实验表征表明，棒状晶体由聚合物链组成，其中Au25 NPs通过线性SR–[Au(I)–SR]4粒间连接体连接在一起。该接头由两个动态分离的SR–[Au(I)–SR]2保护基序与相邻的Au25颗粒共轭形成，并通过CHπ和四乙基铵阳离子与SR配体之间的离子配对相互作用的组合而稳定。通过改变四烷基铵阳离子的浓度和类型，可以系统地调节所得超晶体的对称性、形态和尺寸。

附：英文原文

Title: Supercrystal engineering of atomically precise gold nanoparticles promoted by surface dynamics

Author: Yao, Qiaofeng, Liu, Lingmei, Malola, Sami, Ge, Meng, Xu, Hongyi, Wu, Zhennan, Chen, Tiankai, Cao, Yitao, Matus, Mara Francisca, Pihlajamki, Antti, Han, Yu, Hkkinen, Hannu, Xie, Jianping

Issue&Volume: 2022-11-10

Abstract: The controllable packing of functional nanoparticles (NPs) into crystalline lattices is of interest in the development of NP-based materials. Here we demonstrate that the size, morphology and symmetry of such supercrystals can be tailored by adjusting the surface dynamics of their constituent NPs. In the presence of excess tetraethylammonium cations, atomically precise [Au25(SR)18] NPs (where SR is a thiolate ligand) can be crystallized into micrometre-sized hexagonal rod-like supercrystals, rather than as face-centred-cubic superlattices otherwise. Experimental characterization supported by theoretical modelling shows that the rod-like crystals consist of polymeric chains in which Au25 NPs are held together by a linear SR–[Au(I)–SR]4 interparticle linker. This linker is formed by conjugation of two dynamically detached SR–[Au(I)–SR]2 protecting motifs from adjacent Au25 particles, and is stabilized by a combination of CHπ and ion-pairing interactions between tetraethylammonium cations and SR ligands. The symmetry, morphology and size of the resulting supercrystals can be systematically tuned by changing the concentration and type of the tetraalkylammonium cations.

DOI: 10.1038/s41557-022-01079-9

Source: https://www.nature.com/articles/s41557-022-01079-9