Synthesis and structure of Au_(19)Ag_4(S-Adm)_(15) nanocluster:Polymorphs and optical properties

摘要

Polymorphism is a common phenomenon in nature.Here,we report one-pot wet chemical method to synthesize two polymorphs of Au_(19)Ag_(4)(S-Adm)_(15) nanocluster protected by 1-adamantanethiol(HSAdm),which adopt P-1 and P2_(1)/c space group respectively.The crystal structures of two polymorphs were determined by X-ray crystallography.Compared to the previously reported Au_(19)Ag_(4)(S-Adm)_(15)nanocluster adopting P2_(1)/n space group,polymorphs of Au_(19)Ag_(4)(S-Adm)_(15) with P-1 and P2_(1)/c space group show the different optical properties.Moreove r,Au_(19)Ag_(4)(S-Adm)_(15) with P-1 space group exhibits good thermal stability.Meanwhile,we investigated the effect of solvent and molar ratio of metal precursors on the polymorphs.This work provides an insight to polymorphs of metal nanoclusters.