Jupally Vijay Reddy, Dass Amala
Department of Chemistry and Biochemistry, University of Mississippi, MS 38677, USA.
Phys Chem Chem Phys. 2014 Jun 14;16(22):10473-9. doi: 10.1039/c3cp54343a.
Gold nanomolecules with a precise number of metal atoms and thiolate ligands are being used for catalysis, biosensing, drug delivery and as alternative energy sources. Highly monodisperse products, with reproducible synthesis and complete characterization, are essential for these purposes. Post synthetic etching is used to synthesize highly stable gold nanomolecules. We report a synthetic protocol for the scalable synthesis of Au130(SR)50 for the first time, by etching of larger clusters via a core conversion process. Au130(SR)50 is not present in the crude product, but, is exclusively formed by etching larger clusters (>40 kDa). This is the first evidence that larger nanocluster cores convert to Au130(SR)50. The special stability of Au130(SR)50 is confirmed by the formation of Au130-x(metal)x(SR)50, where R = CH2CH2Ph, C6H13, C12H25 and metal = Ag, Pd. AuxAg130-x(SR)50 is isolated and characterized with two different Au : Ag precursor ratios. Upon alloying there is a change in the optical features of this 130-metal atom nanomolecule. To understand the process of etching and core conversion, a possible mechanism is being proposed. Highly stable nanomolecules like this can find potential applications in high temperature catalysis and sensing.
具有精确数量金属原子和硫醇盐配体的金纳米分子正被用于催化、生物传感、药物递送以及作为替代能源。对于这些用途而言，具有可重复合成和完整表征的高度单分散产物至关重要。合成后蚀刻用于合成高度稳定的金纳米分子。我们首次报告了一种通过核心转化过程蚀刻较大簇来可扩展合成Au130(SR)50的合成方案。Au130(SR)50不存在于粗产物中，而是仅通过蚀刻较大簇（>40 kDa）形成。这是较大纳米簇核心转化为Au130(SR)50的首个证据。Au130(SR)50的特殊稳定性通过Au130-x(金属)x(SR)50的形成得到证实，其中R = CH2CH2Ph、C6H13、C12H25且金属 = Ag、Pd。AuxAg130-x(SR)50通过两种不同的Au:Ag前驱体比例进行分离和表征。合金化后，这种130个金属原子的纳米分子的光学特征会发生变化。为了理解蚀刻和核心转化过程，正在提出一种可能的机制。像这样高度稳定的纳米分子在高温催化和传感方面可能具有潜在应用。
