Understanding Ligand-Exchange Reactions on Thiolate-Protected Gold Clusters by Probing Isomer Distributions Using Reversed-Phase High-Performance Liquid Chromatography

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• 作者：Yoshiki Niihori ; Yoshihiro Kikuchi ; Ayano Kato ; Miku Matsuzaki ; Yuichi Negishi
• 刊名：ACS Nano
• 出版年：2015
• 出版时间：September 22, 2015
• 年：2015
• 卷：9
• 期：9
• 页码：9347-9356
• 全文大小：688K
• ISSN：1936-086X

文摘

Thiolate-protected gold clusters (Au_n(SR)_m) have attracted considerable attention as functional nanomaterials in a wide range of fields. A ligand-exchange reaction has long been used to functionalize these clusters. In this study, we separated products from a ligand-exchange reaction of phenylethanethiolate-protected Au₂₄Pd clusters (Au₂₄Pd(SC₂H₄Ph)₁₈), in which Au₂₅(SR)₁₈ is doped with palladium, into each coordination isomer with high resolution by reversed-phase high-performance liquid chromatography. This success has enabled isomer distributions of the products to be quantitatively evaluated. We evaluated quantitatively the isomer distributions of products obtained by the reaction of Au₂₄Pd(SC₂H₄Ph)₁₈ with thiol, disulfide, or diselenide. The results revealed that the exchange reaction starts to occur preferentially at thiolates that are bound directly to the metal core (thiolates of a core site) in all reactions. Further study on the isomer-separated Au₂₄Pd(SC₂H₄Ph)₁₇(SC₁₂H₂₅) revealed that clusters vary the coordination isomer distribution in solution by the ligand-exchange reaction between clusters and that control of the coordination isomer distribution of the starting clusters enables control of the coordination isomer distribution of the products generated by ligand-exchange reactions between clusters. Au₂₄Pd(SC₂H₄Ph)₁₈ used in this study has a similar framework structure to Au₂₅(SR)₁₈, which is one of the most studied compounds in the Au_n(SR)_m clusters. Knowledge gained in this study is expected to enable further understanding of ligand-exchange reactions on Au₂₅(SR)₁₈ and other Au_n(SR)_m clusters.