Prediction Of Structure And Related Properties Of Gold Nanoclusters Protected By Alkyne Ligands

In recent years,the study of structure-property relationship and cluster growth law in nanoclusters is one of the most critical scientific issues in the field of clusters.In view of the huge application potential of ligand-protected gold nanoclusters in the fields of catalysis,sensing,fluorescent labeling and biomedicine.Therefore,the research on ligand-protected gold nanoclusters is one of the areas of focus for experimental and theoretical workers.In this paper,we use density functional theory to deeply explore the structure,growth rule,and optical properties of various alkyne-protected gold nanoclusters.The first part uses density functional theory?DFT?to predict the alkyne-protected gold nanoclusters in two types of face-centered cubic?FCC?and icosahedral configurations.Through a comparative study of Au₄₄?Ph C?C?₂₈,Au₃₆?Ph C?C?₂₄,Au₂₂?^tBu C?C?₁₈ and Au₂₂?ETP?₁₈ four alkyne-protected gold nanoclusters that have been synthesized in the experiment and thiolate-protected gold nanoclusters with the same proportion,Discover the similarities and differences of the nanocluster skeletons,and summarize the various coordination modes of alkyne ligands and gold atoms.Summarizing the growth rules of acetylene-protected gold nanoclusters in the face centered cubic?FCC?configuration,and found the"alkyne hat rule",And it is used to predict the nano-cluster structure of five FCC structures that have not been synthesized in the two formulas Au_8n+4?C?CR?_4n+8?n=3–6?and Au_16+6n?C?CR?_16+2n?n=1–4?.The calculation of time-dependent density functional theory?TD-DFT?shows that the UV-Vis absorption spectrum of the predicted structure,the characteristic absorption peak of each series of cluster structure has a clear red-shift trend with the increase of cluster size.The second part uses density functional theory?DFT?to conduct theoretical research on the structure and alloying of alkyne protected large-sized gold nanoclusters.According to the similarities and differences between the cores and staple units of Au₁₄₄?C?CR?₆₀ and Au₁₄₄?SR?₆₀nanoclusters synthesized by experiments.The corresponding laws are summarized to apply to the prediction of the structure of large-sized Au₁₀₂?C?CR?₄₄,Au₁₃₃?C?CR?₅₂,Au₁₃₀?C?CR?₅₀nanoclusters for alkyne protection.The bond length analysis of the predicted alkyne ligand-protected nanoclusters showed that the bond length and bond angles of the nanoclusters protected by the thiolate with the isotype ratio were basically the same.At the same time,Au₁₄₄?C?CR?₆₀ clusters are taken as an example to conduct theoretical research on alloying.According to the results of previous studies on Au₁₄₄?SR?₆₀ alloying,Ag or Cu atoms were doped at different sites and shells of Au₁₄₄?C?CR?₆₀cluster.The research results show that the formation energy of Au_?144,145?-xT_x?C?CR?₆₀?T=Cu or Ag?is the lowest when the Cu or Ag atoms are doped in the anti-Mackay?AM,60 site?shell,especially for Ag atoms,only half of the Au₁₄₄?C?CR?₆₀formation energy.At the same time,all the structural models are calculated by simplified time-dependent density functional theory?s TDDFT?,and the theoretically simulated ultraviolet-visible absorption spectrum is obtained.The series of models doped with Cu or Ag atoms produce SPR plasma absorption peaks.