Crystal structure of Au25(SePh)18 nanoclusters and insights into their electronic, optical and catalytic properties

Abstract

The crystal structure of selenolate-capped Au₂₅(SePh)₁₈⁻ nanoclusters has been unambiguously determined for the first time, and provides a solid basis for a deeper understanding of the structure–property relationships. The selenolate-capped Au₂₅ cluster shows noticeable differences from the previously reported Au₂₅(SCH₂CH₂Ph)₁₈⁻ counterpart, albeit both share the icosahedral Au₁₃ core and semi-ring Au₂(SeR)₃ or Au₂(SR)₃ motifs. Distinct differences in the electronic structure and optical, catalytic and electrochemical properties are revealed by the coupling experiments with density functional theory (TD-DFT) calculations. Overall, the successful determination of the Au₂₅(SePh)₁₈⁻ structure removes any ambiguity about its structure, and comparison with the thiolated Au₂₅ counterpart helps us to further understand how the ligands affect the properties of the nanocluster.