Unlike nucleation and growth in simple precipitation processes, described by the classical theory, metal nanoparticles formed in organic solvents with capping ligands often involve chemical reactions that occur homogeneously in solution or heterogeneously on the metal surface. These chemical reactions lead to the formation of intermediates that occurs in the process of deposition onto nuclei during the reduction. The understanding of these chemical reactions would enable a better design of functional metal nanocrystals, even those with unconventional hierarchical morphologies. In this study, we report the formation of dish-shaped nanostructures of palladium (Pd) obtained from palladium acetylacetonate (Pd(acac)₂) in the presence of oleylamine and oleic acid. The process was correlated with the kinetic-controlled evolution of two-dimensional (2D) Pd nanosheets. The formation of Pd-ligand complexes was revealed using single-crystal X-ray diffraction, ultraviolet-visible spectroscopy, and mass spectrometry. These intermediates affected the formation kinetics of the 2D nanostructures and higher-ordered morphology of the nanodishes.

中文翻译：

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通过金属离子-配体络合的碟状高阶钯纳米结构

与经典理论描述的简单沉淀过程中的成核和生长不同，在具有封端配体的有机溶剂中形成的金属纳米粒子通常涉及在溶液中均匀或非均匀地在金属表面上发生的化学反应。这些化学反应导致形成中间体，该中间体在还原过程中沉积到核上的过程中发生。对这些化学反应的理解将能够更好地设计功能性金属纳米晶体，甚至具有非常规分层形态的金属纳米晶体。在这项研究中，我们报告了从乙酰丙酮钯（Pd（acac）₂）在油胺和油酸的存在下。该过程与二维（2D）Pd纳米片的动力学控制演化有关。使用单晶X射线衍射，紫外可见光谱和质谱法揭示了Pd-配体络合物的形成。这些中间体影响了2D纳米结构的形成动力学和纳米盘的更高阶形态。