Silver Clusters Constructed By Perfluorodicarboxylic Acid And Their Optical And Electrical Properties

In recent years,silver clusters have attracted extensive attention due to their attractive structure and excellent optical and electrochemical properties.They are usually composed of metal cluster cores formed by the interaction between silver and silver metals,surface protective ligands and counterbalance ions,among which the metal cluster cores and surface ligands are crucial to the structure and properties of clusters.The flexible perfluorinated dicarboxylic acid ligands with various coordination modes can be used to construct various types of silver clusters,including silver nanoclusters protected by total carboxylic acid,one-dimensional,two-dimensional and three-dimensional coordination polymers based on silver clusters,etc.Therefore,in this paper,a series of flexible perfluorinated dicarboxylic acid ligands were used to construct silver clusters with different dimensions,different core structures of silver clusters and different optical and electrical properties,and their structures and properties were regulated by the coordination mode and carbon chain length of the flexible ligands.The main research contents of the thesis include:(1)Hexafluoroglutaric acid was selected as the protective ligand,and the fully carboxylic acid-protected silver nanoclusters were constructed by solvothermal reaction with silver nitrate in a weak base reduction atmosphere.Its molecular formula was determined as{[(CH₃)₂NH₂]₆[Ag₈(C₅F₆O₄)₆]}·H₂O·6DMF(1)by single crystal diffraction and high resolution mass spectrometry.The cluster core is a rare Ag₈⁶⁺ rhombohedron whose surface is protected by six hexafluoroglutarate groups through the coordination mode of cis-?₄-?¹,?¹,?¹,?¹.The study of its luminescence performance shows that the silver nanocluster protected by organic carboxylic acid has excellent room temperature photoluminescence properties,solid state fluorescence quantum yield is 39.1%,fluorescence lifetime is 0.191ms,and it is a kind of fluorescent materials with potential application value.Related research has developed a simple method to prepare new silver nanoclusters,and opened the way for the discovery of more new organic carboxylic acid-protected coin metal nanoclusters.(2)The one-dimensional coordination polymers[Ag₁₁(C?C^tBu)₇(C₅F₆O₄)₂]_n(2)and the two-dimensional coordination polymers[Ag₆(C?C^tBu)₄(C₉F₁₄O₄)]_n(3)based on the acetylene silver cluster were obtained by adding hexafluoroglutaric acid and tetrafluorononazoic acid into the tert-butyl silver system,respectively.The thermal decomposition temperatures of the two clusters were 250? and 270?,respectively,which showed good thermal stability.The study of its optical properties shows that the energy gaps of the two cluster compounds are 2.23eV and 2.38eV,respectively,and the solid powders both emit yellow fluorescence at low temperatures.Related research has developed related methods for the construction of silver-based MOFs with flexible ligands,which provides a direction for the study of their structure control and performance.(3)The two-dimensional coordination polymers[Ag₍14_C9F14O44(SPrⁱ)₆·8DMF]_n(4)and the three-dimensional coordination polymers[Ag₁₄(C₁₀F₈O₄)-4(SPrⁱ)₆·6DMF]_n(5)based on the sulfur silver cluster were obtained by adding octafluoroadipic acid and tetradecafluoroazelaic acid into the isopropyl sulfide silver system,respectively.While studying the structure and performance,their superelectric properties are mainly studied.The specific capacitances are 372Fg^-1 and 412Fg^-1,respectively,and exhibit high cycle stability.Related research results provide a reference for the development of high-performance supercapacitor electrode materials based on conductive metal clusters.