The positional isomerism in bimetal nanoclusters

Abstract

Enriching the variety of isomerism in the nanocluster field is exciting but challenging. In this work, for the first time we graft the concept of positional isomerism in organic molecules onto thiolate-stabilized nanoclusters and report such positional isomerism. The structure of the novel nanocluster Au₁₂Ag₃₂(2-EBT)₂₆(PPh₃)₄ (2-EBTH = 2-ethylbenzenethiol) was characterized by single crystal X-ray crystallography. The result indicated that the prepared nanocluster Au₁₂Ag₃₂(2-EBT)₂₆(PPh₃)₄ has the same Ag/Au molar ratio as the existing Au₁₂Ag₃₂(3,4-DFT)₃₀ (3,4-DFTH = 3,4-difluorothiophenol) nanocluster but with an entirely different surface structure. Interestingly, another fascinating structural feature in Au₁₂Ag₃₂(2-EBT)₂₆(PPh₃)₄ is the presence of chirality, which is a particular distinguishing structural characteristic among the reported bimetal nanoclusters to the best of our knowledge.