Synthesis,Characterization And Total Structure Of Ag₇₁ Nanoclusters Protected Via Dual Ligand

At present,it has become possible to precisely control the size and composition of metal nanoclusters at the atomic level.Through the combination of inner core metal atoms（Au/Ag/Cu,etc）and peripheral ligands（thiol/phosphine/halogen atoms/alkynes,etc）,metal nanoclusters with different sizes,structures and compositions are expected to be obtained.Therefore,Au and Ag nanoclusters have good potential application prospects in the fields of liquid phase catalysis and biological detection.Based on previous studies,this paper selects silver nanoclusters protected by thiol and phosphine ligands for research.The main research contents of this paper are as follows:The[Ag₇₁（S-^tBu）₃₁（Dppm）]（SbF₆）₂ nanoclusters with decahedron core were successfully synthesized by the liquid-phase direct synthesis method(Dppm=Bis（diphenylphosphino）methane,S-^tBu=tert-butyl mercaptan;abbreviation as Ag₇₁cluster).Using Na BH₄ as a reducing agent,Ag NO₃ was mixed with 1,1-（bis-diphenylphosphino）methane and tert-butyl mercaptan ligands,Ag₇₁clusters were prepared via one-pot method.And their structure was determined by X-ray single crystal diffraction.Sliver nanoclusters co-capped by dppm and other ligands have rich forms.In this paper,the Ag₇₁nanoclusters protected by two ligands,S-^tBu and Dppm,show an unusual structural patterns.First,a decahedron Ag₂₃kernel combining with an Ag₁₀@Ag₅@Ag₁lid and an Ag₁₀ring constitute Ag₄₉shells,similar the Marks decahedron on M₇@M₄₂（M=Au/Ag）shells in other larger nanoclusters.Second,for another anatomy,the Ag₂₄kernel(like Ag₂₅losing a vertex Ag atom)was enclosed by four layers(Ag₅,Ag₁₀,Ag₂₀and Ag₁₀)surrounded by SR ligands and Ag₂Dppm staple.Importantly,the building group Ag₆₄observed in Ag₇₁（SR）₃₁（Dppm）]²⁺can be assembled to generate larger cores for the construction of larger silver nanoclusters,such as Ag₁₃₆（SR）₆₄Cl₃and Ag₁₄₁（SR）₄₀Br₁₂.The large assembly unit Ag₆₄provides a new assembly method that can predict the structure of larger nanoclusters,and the first observed of a full decahedron in nanoclusters less than 100atoms provides an deepen understanding on Marks decahedron truncation,and a chance to predict the structure.