Synthesis Of Gold-silver Alloy Nanoclusters And Their Response To Specific Lewis Bases

The atomic-level precise noble metal nanoclusters protected by organic ligands have a size ranging from 1 to 3 nm.The quantum size effect leads to energy level separation and has unique physical and chemical properties.Among them,chirality,magnetism and photoluminescence have attracted the attention of researchers,and have been widely used in the fields of biology,catalysis,and sensing.The application of noble metal nanoclusters in the field of sensing is mainly based on changes in their optical properties（for example,the substance under test quenches the fluorescence of noble metal nanoclusters）.However,existing reports have shown that the structure of noble metal nanoclusters is at this point.The process is destroyed and its optical properties are changed.The noble metal nanoclusters no longer have the ability of photoluminescence,which makes the noble metal nanoclusters unable to achieve recyclable detection,it is expensive for sensing and detection.Therefore,the realization of the cyclic detection of foreign substances without destroying the structure of the metal cluster is of great significance for its application in the field of sensing.In this paper,based on the control of organic ligands as the design concept,with dimethylboryne as the protective ligand,a new type of alloy nanocluster with stable structure and responsive to specific Lewis bases was synthesized.The main contents are as follows:（1）We successfully synthesized a gold-silver alloy nanocluster by using the co-reduction method of metal complexes.The structure was characterized by X-ray single crystal diffraction,and the results showed that the alloy nanoclusters were Au₈Ag₈（Mes）₁₆;the basic optical properties were measured by ultraviolet-visible spectrophotometer and fluorescence spectrophotometer,and the results showed that the alloy nanoclusters were Au₈Ag₈（Mes）₁₆.The alloy nanoclusters have photoluminescence properties,the fluorescence emission peak is 510 nm,and the quantum yield in dichloromethane is 21%;the clusters show good stability in solution.（2）We tested the response of Au₈Ag₈（Mes）₁₆ alloy nanoclusters to specific Lewis bases（fluoride ions,tetrahydrofuran and pyridine）,and the results showed that the alloy nanoclusters have good responsiveness to fluoride ions.By comparing with Au₈Ag₈（DTBPh）₁₆,which has the same metal core structure,the response mechanism of the new alloy nanoclusters was studied,and it was determined that the two-meter-based boryne ligand realized the functionalization of the alloy nanoclusters.At the same time,the alloy metal nanocluster has a stable structure and has a cyclic response ability to fluoride ions.This work is of great significance for the functionalization of noble metal nanoclusters.In summary,in the field of noble metal nanocluster sensing,this work used ligands with specific functions（such as response to fluoride ions）to synthesize new alloy nanoclusters without destroying their structure.The realization of the response to a specific Lewis base is of great significance for expanding the application of noble metal nanoclusters in the field of sensing.