Preparation Of Series Of 1,3,5-Trithiane Ligated Silver Clusters And Their Luminescence Properties

Silver clusters have attracted wide attention from researchers due to their novel structure,special properties and broad potential application value.In the construction of silver clusters,the nature of the ligand determines the composition,molecular formula,atomic structure and unique properties of the silver cluster protected by the ligand.Exploring and developing novel silver clusters controlled by new ligands is a hot spot in the field of cluster chemistry research.Compared with the thiol ligands widely used in the construction of silver clusters,this paper takes the lead in using neutral cyclic thioether 1,3,5-trithiane as the protective ligand,based on the silver alkyne and silver sulfide system,a series of silver clusters were synthesized by solvothermal method,the crystal structure of the clusters was characterized and discussed,and the ultraviolet and fluorescence properties of the clusters were studied.The specific research content and results of this article are as follows:(1)A simple tetranuclear silver cluster(cluster 1)was prepared by solvothermal method with PhC2Ag,soluble silver salt AgOTf and 1,3,5-trithiane ligand.Through the study of the ultraviolet and fluorescent properties of the cluster compound,it was found that it has good ultraviolet-visible light absorption capacity and fluorescent properties at room temperature and low temperature.In addition,thermogravimetric characterization shows that the decomposition temperature is 210?,and it has good thermal stability.The cluster compound 1 has good thermal stability and stable structure,and is expected to be used as a multi-dimensional coordination polymer as a group of structural units,which provides a direction for the synthesis and design of such coordination polymers.(2)Based on the study of the structure and properties of tetranuclear silver clusters regulated by 5-trithiane ligands in chapter 3,a one-dimensional coordination polymer based on low-core silver clusters(cluster 2)and a two-dimensional coordination polymer(cluster 3)were successfully synthesized.Both cluster compounds have semiconductor properties,and the two-dimensional cluster compound has thermochromic properties and good thermal stability.Based on the study of the structure and properties of tetranuclear silver clusters regulated by 1,3,5-trithiane ligands in Chapter.It is found that the ligands have special coordination modes ?4-?1,(cis-?1,?1,?1)and ?3?1,(cis-?1,?2).They can chelate and fix metal nuclear clusters and act as bridging ligands to form cluster-based polymers,thus realizing the construction of multi-dimensional coordination polymers based on simple low-nuclear silver clusters.(3)Based on the precursor C?C'BuAg and the soluble silver salt system,and using 1,3,5trithiane as the protective ligand,an atomically accurate silver nanocluster(cluster 4)and a eutectic nanocluster(cluster 5)were successfully prepared,which was the first realization.Based on the synthesis of silver nanoclusters protected by 1,3,5-trithiane ligands,the nanosilver core clusters of the two clusters are all octahedral cage structures.It is novel that cluster 5(co-crystal cluster)and cluster 4 have similar silver nanoclusters,and there is another similar hexagonal octahedral cagelike silver cluster in the crystal cell of cluster 5.In the process of synthesizing clusters,similar independent nuclear clusters(with similar nuclear number and structure)formed by the same metal and ligand types can be precipitated together in the same cell to form eutectic clusters because of their similar lattice energy.it provides an idea for the synthesis of eutectic metal clusters.In addition,we have studied the UV and fluorescence properties of two nanoclusters,and found that they all have strong UV-visible light absorption and fluorescence properties at room temperature and low temperature,which is related to the zero-valent silver in the two clusters.