Synthesis,Structures And Properties Of Gold And Gold-silver Clusters

Special structures and properties of clusters make them possible for applications in catalysis,sensing,superconducting materials,OLED,biolabeling,etc.Coinage metal clusters have been one of the focuses on clusters due to their unique geometric structures,electronic structures and optical properties.The relationship between structures and optical properties of Au12Ag12 clusters is discussed in this dissertation,and the dissertation focuses on the synthesis,structures and optical properties of the mixed-valence gold nanoclusters and gold-silver nanoclusters.The main findings and results are as follows:(1)By comparing structures and optical properties of Au12Ag12(C=CPh)12(SiPr)12 cluster and its congeners,discuss effects on the differences between ligands.(2)By synthesizing alky nyl-protected Au36(C=CPh)24,Au24Ag20(C=Cth)24 and Au26Ag20(C=CPh)28,discuss effects of ligands on structures and optical properties of coinage metal clusters.Features and advantages of alkynyl groups are also perfectly showed.(3)Mix alkynyl/halide-protected Au80Ag30,Au36Ag36 and Au59Ag51 were synthesized and structurally determined.Au80Ag30 can be dissected in a shell-by-shell manner,with four shells.The chiral metal core M110 is distributed in a concentric four-shell Russian doll arrangement,Au6@Au35@Au18Ag30@Au21.The work about Au80Ag30 demonstrates that halides play an important role in the formation of a large coinage metal nanocluster,and the halide effect should be considered in the design and synthesis of metal nanoclusters.Au36Ag36 and Au59Ag51 also with a core-shell structure show low symmetry but good stability as Au80Ag30.They also show the variety of coinage metal nanoclusters.Halides exhibit diverse coordination modes as well as alkynyl groups,and they prefer to bind silver atoms other than gold atoms in Au/Ag bimetallic nanocluster.