Preparation Of Au(I)-Thiolate Coordination Polymer 2D Colloidal Nano-Assemblies In Organic Solvents

Two-dimensional(2D)nanomaterials are planar materials with a thickness of nanometer level.Their large specific surface area enables them to show different physical and chemical properties from bulk materials,showing considerable application potential in energy,catalysis,sensing and other fields.Through the modification of elements,structure and functional groups,the properties of traditional inorganic 2D nanomaterials can be regulated,and even a new material system can be developed.Different from the above modification methods,Organic Metal Chalcogenides(OMCs)are formed by self-assembly of coinage metal ions and thiolate ligands.The center of the assembly is a metal-sulfur 2D skeleton,with the surface covered by the substituents of thiolate ligands.These nanomaterials have unparalleled advantages over traditional inorganic 2D materials in terms of structure control and performance regulation.In the OMCs materials family,the 2D nanomaterials composed of Au(I)-thiolate coordination polymers(ATCP)have unique stability and optical properties.Their large specific surface area also makes them exhibit excellent performance in the field of sense,especially in chiral sensing in aqueous solutions.After thirty years of development,it has been possible to prepare stable and dispersed ATCP nano-assemblies in the form of colloids in the aqueous phase.However,there are only two reported preparations in the organic phase,both of which are related to the preparation of bulk crystals.What’s more,obtaining assemblies with high structural regularity requires high temperature and pressure conditions,so it is still a challenge to achieve the preparation ATCP 2D assemblies under mild conditions and its colloidal dispersion in organic systems.This paper is committed to exploring the mild method of synthesizing 2D ATCP nano-assemblies in organic phase.In the second chapter,using 1-Pentanethiol(PT)as the thiolate ligand,we investigated the assembly behavior of ATCP by changing solvent,temperature,concentration and other conditions.We found that high temperature can promote the regularity of assembly and crystallization,but the assemblies are also easy to be converted into gold nanoparticles.Therefore,we further explored the method to synthesize assembly in low boiling solvent,and we successfully synthesized Au(I)-PT.Then we verified the feasibility of this method in two new ligands,1-dodecanethiol(DT)and p-mercaptobenzoic acid,realizing the expansion of ligand types preliminarily.Subsequently,we proposed an explanation for the mechanism of ligand exchange assisted crystallization,that is,the attack of free ligands on polymer chains promotes reversible bond breaking to assist crystallization,and we provided experimental evidence using the reactions between Au(I)-PT and Au(I)-DT.Based on the above achievement,in chapter three we propose to reduce the ligand interaction between layers and enhance the interaction between ligands and solvents through the co-assembly of ligands with different sizes,thereby achieving the stable colloidal dispersion of assemblies.By co-assembling two ligands,PT and DT,we explored the effect of different ligand ratios on the colloidal stability of the assembly.We found that under appropriate ligand ratios,co assembly can significantly improve the colloidal dispersion stability of the assembly,providing a material foundation for expanding the application of ATCP 2D assemblies in field of organic phase sensing.In summary,this paper has designed and developed a mild method for preparing Au(I)-thiolate 2D nano assemblies colloids in organic phase,laying a foundation for expanding the application of ATCP 2D nano assemblies in organic phase,and providing important reference for the research and development of other related materials.