Atomic and Isomeric Separation of Thiolate-Protected Alloy Clusters

Yoshiki Niihori; Yuki Koyama; Seiichiro Watanabe; Sayaka Hashimoto; Sakiat Hossain; Lakshmi V Nair; Bharat Kumar; Wataru Kurashige; Yuichi Negishi

doi:10.1021/acs.jpclett.8b02211

Atomic and Isomeric Separation of Thiolate-Protected Alloy Clusters

J Phys Chem Lett. 2018 Sep 6;9(17):4930-4934. doi: 10.1021/acs.jpclett.8b02211. Epub 2018 Aug 16.

Authors

Affiliations

¹ Department of Applied Chemistry, Faculty of Science , Tokyo University of Science , 1-3 Kagurazaka , Shinjuku-ku, Tokyo 162-8601 , Japan.
² Photocatalysis International Research Center , Tokyo University of Science , 2641 Yamazaki , Noda , Chiba 278-8510 , Japan.

PMID: 30066568
DOI: 10.1021/acs.jpclett.8b02211

Abstract

Techniques to control the chemical compositions and geometric structures of alloy clusters are indispensable to understand the correlation between the structures and physical/chemical properties of alloy clusters. In this study, we established a method to separate thiolate-protected 25-atom gold-silver alloy clusters (Au_{25- x}Ag _x(SR)₁₈) according to their chemical composition and structural isomer. Furthermore, using this method, we revealed that an isomeric distribution of the products exists in Au_{25- x}Ag _x(SR)₁₈ ( x ≥ 2) and that the distribution of these isomers depends on the synthesis method and standing time in solution. In this study, it was also demonstrated that the continuous discretization of the electronic structure is induced by the Ag substitution. This method can also be used to separate mixtures of [Au₂₄M(SR)₁₈]⁰ (M = Au, Pt, or Pd) and other Au-Ag alloy clusters ([Au_{36- x}Ag _x(SR)₂₄]⁰ and [Au_{38- x}Ag _x(SR)₂₄]⁰). This method is expected to be used to obtain comprehensive knowledge of the structural-property correlation of alloy clusters.