Syntheses And Characterization Of Bimetallic(0) Clusters Protected By Alkynyl And/or Phosphine

Nanoclusters are a series of nanomaterials with molecule-like property,which are composed of several or hundreds of atoms and are between small molecules and nanoparticles in size.Over the past decades great progress have been witnessed in demonstrating the fine structure of the isolated single crystals of metal nanoclusters as the development of X-ray crystallography.Owing to the multiple inner structure and abundant protected ligands,nanoclusters possess unique optical,electrical and catalytic properties,which makes them potential candidates in many applications such as optical materials,biological fluorescence imaging,sensing detection as well as catalytic material.Herein,we synthesize a series of alkyne and phosphine co-protected and alkynyl-protected bimetallic coin nanoclusters.The main results and contents of this article are summarized as follows:?1?Alkyne-phosphine co-protected biemetallic nanoclustersa: The study of the role of para-alkyl of Alkynyl on the benzene ring in the synthesis and packing mode of Ag-Cu bimetallic NCs.The phenylacetylene with different ethynyl para-alkyl chains-protected Ag-Cu nanoclusters have a core structure of Ag₂₅Cu₄Cl₆.The core has an icosahedron and four Cu Ag3 planes,which are bridged by six chlorine atoms and six Cu atoms in the plane center.The coordination mode of alkynyl ligand is ?₄.However,the packing mode of nanoclusters protected by p-tert-butylphenylacetylene is different from of the other clusters protected by p-methyl,ethyl,and butylphenylacetylene.The molecule packing mode is related to the interaction of the ligands of nanoclusters.Interaction of the clusters protected by p-tert-butylphenylacetylene is between the alkyne ligands and phosphine ligands.Interaction of the clusters protected by methyl-,ethyl-and butyl-phenylacetylene is between the phosphine ligands and phosphine ligands.b: The study of the effects of methyl groups at different positions of phenylacetylene in the bonding mode of alkynyl ligands of Ag-Cu bimetallic NCs.The 3-methylphenylacetylene-protected Ag-Cu nanoclusters have the same core structure as 4-Methylphenylacetylene protected Ag-Cu nanoclusters.The core of the 2-Methylphenylacetylene-protected alloy cluster changed significantly and the coordination mode with the metal was also different.?2?Tert-butylene-protected metal nanoclustersa: A silver cluster protected by an oxyanion and alkynes.The tert-butyne-protected silver cluster Ag₄₃ is a concentric three-core-shell structure Ag@Ag₁₂@Ag₃₀,which contain a icosahedron and a icosidodecahedron.Ag₄₃ is protected by 24 t-butylalkyne and 8 triflate.The cluster has a broad absorption band at 496 nm and 640 nm in the visible region.The size of the cluster is 1.96 nm and has potential catalytic applications.b: The study of the similarities and differences between the structure and catalytic activities of silver,copper and bimetallic clusters protected by tert-butylene.The three structures are all rhombohedral dodecahedrons.The center metal adopts the body-centered cubic stacking mode and coordinate eight metal atoms,and the other six metal atoms cover the surface of the cube to form a virtual octahedron.The catalytic activity of the three nanoclusters for the mode reaction of dehydrogenation coupling of dimethylphenylsilane is different,and the yield of the coupled product is also different.