| Ligand-protected metal nanoclusters have attracted extensive research interest due to their ultra-small size(1-3 nm)and unique molecular-like properties.Its atomically precise structure provides an ideal model system for exploring the surface coordination chemistry of metal nanomaterials,which helps us understand the role of ligands and cores in the construction of metal nanoclusters,and further revealing the relationship between material structure and properties from the atomic level.In this paper,a series of environment-stable gold/copper nanoclusters has been designed and synthesized by regulating ligands and local groups.The core structure of Au nanoclusters and the influence of ligand effects on their catalytic performance were mainly explored,and the core evolution process of a series of Cu nanoclusters were revealed.Furthermore,their nonlinear optical effects,chirality and fluorescence properties were developed through functional regulation of ligands.The main contents are as follows:1.Five cases of gold nanoclusters were synthesized by introducing thiol ligands with rich coordination modes to increasing the diversity and stability of cluster structures in the system of Au nanoclusters protected by organophosphine ligands,which are Au20,Au8,Au25.By comparing of the symmetry of the structure of these five nanoclusters,it has been found that with the increasing of the volume of the organophosphine ligands,the lengthening of the alkyl chain leading to the reduction of the core of Au nanoclusters.However,the types of thiol ligands and the electronic effects of substituents have little effect on the inner core structure.UV-vis spectral tracking showed that the addition of thiol ligands could indeed improve the stability of Au nanoclusters.In addition,the core structure of metal nanoclusters and the influence of ligand effects on its catalytic properties were revealed at the atomic level by exploring of the cluster in the catalytic silane oxidation reaction.2.A new synthetic strategy by introducing bis(triphenylphosphine)cuprous borohydride has been developed,which can be served as a source of organophosphine ligand and took advantage of its weak reducibility at the same time.And 8 cases of zero-valent Cu nanoclusters(Cu13,Cu14,Cu22,Cu32,Cu39,Cu46)were successfully synthesized by secondary reduction.Xray single crystal diffraction indicated that the metal core of this series of Cu nanoclusters had an evolution process from layered stacking to "Cluster of Cluster" growth.Among them,the core of Cu13 to Cu14,Cu22,Cu32 evolved from incomplete FCC accumulation(missing B layer)to FCC-like accumulation mode.For Cu39,the inner core was formed by the fusion of two twisted Cu13 icosahedrons through the growth mode of "Cluster of Cluster".An unprecedented Cu13 deformed double-capped pentaprism was found in the metallic core of Cu46 as the basic building unit,three Cu13 constitute its metal framework based on the growth mode of "Cluster of Cluster".Subsequently,based on the completely asymmetric crystal structure of clusters Cu39-1 and Cu39-2,the nonlinear optical properties of its solution thin films were explored,which is of great significance for studying the development of metal nanoclusters in the field of nonlinear optics at the atomic level.3.An example of a simple chiral copper complex Cu(Binap)(H2O)was synthesized via Rac-2,2’-bis(diphenylphosphino)-1,1’-binaphthyl ligand which can be used as a source of chirality.It was shown that the photoluminescence of the chiral copper complex was caused by the aggregation-induced effect(AIE)by analyzing the optical properties of Cu(Binap)(H2O).On this basis,4,4’-bipyridine ligands were introduced and a copper cluster Cu2(Binap)2(Bipy)(NO3)2NO3 was obtained by a bottom-up assembly strategy,where the NO3acted as a counter anion to balance the charge.This work provides an idea for the synthesis of chiral luminescent metal clusters. |
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