Structure Evolution And Ligand Effects Of ?Au₁L₂?_n,?Au₂L₃?_n,?Au₃L₄?_n?n=1-3,L=SH,SCH₃,P?CH₃?₂,PH₂,Cl? Clusters

It is well known that ligand gold clusters have attracted much attention since they were discovered because of their excellent catalysis and luminescence.However,due to its low synthesis rate,there are not many reports about the synthesis of ligand gold clusters in the experiment.Therefore,the theoretical calculation of ligand gold clusters has played a great role,and it can provide theoretical basis and basis for experiments.In this paper,based on particle swarm optimization with density functional theory?DFT?,we have carried out a systematic theoretical calculation of the gold clusters protected by thiol ligands and a series of ligands protected by different ligands.There are two main contents:1 the structural evolution of[Au₁?SR?₂]_n,[Au₂?SR?₃]_n,[Au₃?SR?₄]_n?n=1-3?clusters;2 the influence of ligands on the gold nanoclusters.The first part of the paper discussed the structure evolution,electronic structure,spectrum and average binding energy of thiol ligand protected[Au₁?SR?₂]_n?[Au₂?SR?₃]_n?[Au₃?SR?₄]_n?n=1-3?.Through the global structure search,the cluster structure in this paper has a"linear-Ring-nuclear stereotyping"evolution trend.It is worth mentioning that the gold core structure of this paper mainly include Au₃,Au₄,Au₆,Au₇,and a Au₃ unit to Au_n evolution tendency through the theoretical calculation,the prediction of[Au₁?SR?₂]_n?[Au₂?SR?₃]_n?[Au₃?SR?₄]_n?n=1-3?clusters off the absorption curve with the experimental results.By comparing the characteristic absorption peaks of infrared visible absorption spectra of clusters,it is known that the infrared spectrum has obvious trend of change with the increase of size,which indicates that the optical properties of the clusters are enhanced.The second part of the paper discusses the influence of ligands on the gold nanoclusters.We analyzed the structure of[Au₁?L?₂]_n?[Au₂?L?₃]_n?[Au₃?L?₄]n?n=1-3,L=SCH₃?Cl?P?CH₃?₂?PH₂?.The structure of the ligand is-SR,and the structure of other ligands is compared with that of the structure.When the ligand is Cl,with the increase of the number of gold atoms,the size of the gold nucleus tends to increase,and the length of the ligand protection chain is reduced.When the ligand is PR₂ and the ligand is Cl,the size of the gold nucleus tends to decrease and the length of the ligand protection chain is increased.In addition,we also found that the influence of-R on cluster structure is very small.It can not be ignored.When we calculate theoretically,we can use small-R atoms to replace complex large-R atoms,and reduce the computation.The effect of ligand on the stability of gold clusters is SH>Cl>PH₂>SCH₃>P?CH₃?₂ by the energy analysis of ligand gold clusters.Through the study on the structure and properties of the ligand gold cluster system,we structure of ligand gold cluster evolution and optical properties have a better understanding and understanding,to further study and explore the ligand gold clusters the physical and chemical characteristics has laid a theoretical research foundation.We hope that the research results in this paper will help other researchers to study more about the structure and properties of ligands,so as to carry out more and deeper research.