金バッキーボールとよく使われるナノ粒子の「種」は同じものである(Gold buckyballs, oft-used nanoparticle ‘seeds’ are one and the same)

2023-08-14 ライス大学

＜関連情報＞

• https://news.rice.edu/news/2023/gold-buckyballs-oft-used-nanoparticle-seeds-are-one-and-same
• https://www.nature.com/articles/s41467-023-40016-3

原子レベルで精密なナノクラスターが金ナノ粒子合成の主流に Atomically precise nanoclusters predominantly seed gold nanoparticle syntheses

Liang Qiao,Nia Pollard,Ravithree D. Senanayake,Zhi Yang,Minjung Kim,Arzeena S. Ali,Minh Tam Hoang,Nan Yao,Yimo Han,Rigoberto Hernandez,Andre Z. Clayborne & Matthew R. Jones
Nature Communications  Published:21 July 2023
DOI:https://doi.org/10.1038/s41467-023-40016-3

Abstract

Seed-mediated synthesis strategies, in which small gold nanoparticle precursors are added to a growth solution to initiate heterogeneous nucleation, are among the most prevalent, simple, and productive methodologies for generating well-defined colloidal anisotropic nanostructures. However, the size, structure, and chemical properties of the seeds remain poorly understood, which partially explains the lack of mechanistic understanding of many particle growth reactions. Here, we identify the majority component in the seed solution as an atomically precise gold nanocluster, consisting of a 32-atom Au core with 8 halide ligands and 12 neutral ligands constituting a bound ion pair between a halide and the cationic surfactant: Au₃₂X₈[AQA⁺•X^–]₁₂ (X = Cl, Br; AQA = alkyl quaternary ammonium). Ligand exchange is dynamic and versatile, occurring on the order of minutes and allowing for the formation of 48 distinct Au₃₂ clusters with AQAX (alkyl quaternary ammonium halide) ligands. Anisotropic nanoparticle syntheses seeded with solutions enriched in Au₃₂X₈[AQA⁺•X^–]₁₂ show narrower size distributions and fewer impurity particle shapes, indicating the importance of this cluster as a precursor to the growth of well-defined nanostructures.