Single-Source Precursors for Alloyed Gold–Silver Nanocrystals - A Molecular Metallurgy Approach

Multiple silver­(I)-aurates­(I) have been prepared by salt metathesis reactions that act as efficient single-source precursors to colloidal gold silver alloys with the highest possible atom economy in the chemical synthesis of nanostructures. The CF3 group present on the Au cation acts as an in situ reducing agent and can be converted into CO ligands by simple hydrolysis. This ligand-mediated activation and subsequent decomposition of metal–organic precursors impose a molecular control over the nucleation process, producing homogeneously alloyed (Ag–Au) nanoparticles with an atomic Au:Ag ratio of 1:1. The concept also works for the Au–Cu system and acts as a pointer to replace Au (Ag) with less expensive (Cu) metals.

本研究通过复分解反应（salt metathesis reaction）制备了多种银(Ⅰ)-金(Ⅰ)酸盐，其可作为高效单源前驱体（single-source precursors）用于胶体金银合金的合成，在纳米结构的化学合成中实现了最优原子经济性。金阳离子所连的三氟甲基可作为原位还原剂，经简单水解即可转化为一氧化碳配体。该配体介导的活化过程与后续金属有机前驱体（metal–organic precursors）的分解，可对纳米颗粒成核过程实现分子级精准调控，最终得到原子比Au:Ag=1:1的均匀合金化银-金纳米颗粒。此策略同样适用于金-铜双金属体系，为使用廉价金属铜替代金、银提供了可行的研究方向。