Solea Atena B, Dermutas Davide, Fadaei-Tirani Farzaneh, Leanza Luigi, Delle Piane Massimo, Pavan Giovanni M, Severin Kay
Institut des Sciences et Ingénierie Chimiques, École Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland.
Department of Applied Science and Technology, Politecnico di Torino, Torino 10129, Italy.
Nanoscale. 2025 Jan 2;17(2):1007-1012. doi: 10.1039/d4nr03901g.
Multilayer vesicles with an onion-like architecture can form by self-assembly of organic amphiphiles such as dendrimers, small-molecule surfactants, and block copolymers. Thus far, there are limited reports about multilayer vesicles based on coordination compounds. Herein, we show that nano onions are obtained by aggregation of an amphiphilic Au(pyrazolate) complex in aqueous solution. The nanostructures were characterized by cryogenic and transition electron microscopy, dynamic light scattering, and energy-dispersive X-ray analysis. Control experiments with analogous Ag(I) and Cu(I) complexes revealed the importance of Au(I) for the formation of well-defined nano onions. A structurally related Au(I) complex without solubilizing polyethylene glycol side chains was analyzed by single-crystal X-ray diffraction. In the solid state, columns of offset, π-stacked Au(pyrazolate) complexes are observed, but short intermolecular Au⋯Au contacts were not found. Molecular dynamics simulations provided further insights into the aggregation process in aqueous solution, supporting the formation of nano-onion structures through lateral interactions between stacked complexes.
具有洋葱状结构的多层囊泡可通过树枝状聚合物、小分子表面活性剂和嵌段共聚物等有机两亲物的自组装形成。到目前为止，关于基于配位化合物的多层囊泡的报道有限。在此，我们表明纳米洋葱是由两亲性Au（吡唑酸盐）配合物在水溶液中聚集而成的。通过低温和透射电子显微镜、动态光散射和能量色散X射线分析对纳米结构进行了表征。用类似的Ag（I）和Cu（I）配合物进行的对照实验揭示了Au（I）对于形成明确的纳米洋葱的重要性。通过单晶X射线衍射分析了一种没有增溶聚乙二醇侧链的结构相关的Au（I）配合物。在固态中，观察到错位的、π堆积的Au（吡唑酸盐）配合物柱，但未发现短的分子间Au⋯Au接触。分子动力学模拟为水溶液中的聚集过程提供了进一步的见解，支持通过堆叠配合物之间的横向相互作用形成纳米洋葱结构。
