羧酸保护银纳米团簇的形成机制及其构效关系研究

来源丰富、便宜易得、生物相容性好的羧酸，是一类制备银纳米团簇的优良保护配体。但由于软硬酸碱规则的限制，羧酸保护银纳米团簇的制备存在稳定性差和分离结晶困难等问题难以解决。本课题组率先揭示了全羧酸保护的银纳米团簇的结构，该研究结果激发我们进一步探索有机单羧酸/氨基酸保护的银纳米团簇。本项目提出利用羧酸R基团的空间位阻调控羧基与银离子的反应性，利用醇/碱低温溶剂热条件提供的弱还原氛围以及氢键等超分子相互作用提供的额外稳定性因素解决羧酸保护银纳米团簇的形成和稳定性问题，在制备有机单羧酸/氨基酸保护银纳米团簇的同时，通过质谱等手段研究其形成机制，利用单晶等手段表征其精确的分子结构，并研究其结构和性能之间的关系。本项目研究将扩大羧酸类配体的使用范围，全面揭开羧酸类配体保护银纳米团簇结构的面纱，丰富币金属纳米团簇的种类，开拓币金属纳米团簇研究的新方向，对于深刻理解银纳米材料的光学性能具有重要意义。

The great availability, affordability, biocompatibility, and variety of carboxylic groups make them become ideal protecting ligands for preparing silver nanoclusters. However, the classic hard-soft-acid-base (HSAB) theory tells us that the interaction between the hard base-type carboxylate groups and the soft acid-type Ag atoms is weak. The poor stability and the separate crystallization problems of carboxylate-protected silver nanoclusters (CAgNCs) are left unsolved by a previous study. Our previous work realized the construction of the first all carboxylate-protected silver nanoclusters, and promote us further constructing CAgNCs with organic mono-carboxylate acids or amino acids. This project proposes that the reactivity between the carboxylates and Ag+ will be improved by increasing steric hindrance of the R groups of carboxylic acids. And the weak reduction activity should be provided for the formation of CAgNCs by the solvothermal method under alcohol/alkaline conditions, and the hydrogen bonding supramolecular interactions can provide additional stability to the formation of CAgNCs. New organic mono-carboxylate acids or amino acids protected CAgNCs will be prepared, their formation mechanism will be revealed by ESI-MS, their atomically precise structures will be determined by X-ray single diffraction, and the relationships between their structures and properties will be studied. This project will expand the serviceable range of carboxylate ligands, opening the door to using carboxylate groups to synthesize atomically precise Ag nanoclusters, enrich the category of coinage metal nanoclusters, and have widened the study scope of coinage metal nanoclusters. The study result is significant to further understand the optical properties of silver nanomaterials.