A polymer ligand–based strategy enables assembly of nanoscale particles into configurations reminiscent of molecules. Self-limiting bonding Although many routes have been developed to link together colloidal particles into controlled superstructures from dimers all the way up to three-dimensional lattices, they generally depend on coating the nanoparticle surfaces in specific ways to control the way they link up. By contrast, Yi et al. developed a ligand chemistry such that, when two particles link together, it changes the electrostatic properties to limit subsequent bonding (see the Perspective by Gang). Particles are coated with complementary polymer strands that undergo an acid-base neutralization reaction. This bonding is controlled by the length of the flexible ligands, whereas the arrangement of the bonded particles is controlled by electrostatic repulsions, thus giving two parameters to tune the shape of the assemblies that form. Science, this issue p. 1369; see also p. 1305 Nanoparticle clusters with molecular-like configurations are an emerging class of colloidal materials. Particles decorated with attractive surface patches acting as analogs of functional groups are used to assemble colloidal molecules (CMs); however, high-yield generation of patchy nanoparticles remains a challenge. We show that for nanoparticles capped with complementary reactive polymers, a stoichiometric reaction leads to reorganization of the uniform ligand shell and self-limiting nanoparticle bonding, whereas electrostatic repulsion between colloidal bonds governs CM symmetry. This mechanism enables high-yield CM generation and their programmable organization in hierarchical nanostructures. Our work bridges the gap between covalent bonding taking place at an atomic level and colloidal bonding occurring at the length scale two orders of magnitude larger and broadens the methods for nanomaterial fabrication.

中文翻译：

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由反应化学计量控制的自限性定向纳米颗粒键合

基于聚合物配体的策略能够将纳米级粒子组装成类似分子的结构。自限性键合 尽管已经开发出许多途径将胶体颗粒连接在一起形成受控的超结构，从二聚体一直到三维晶格，但它们通常依赖于以特定方式涂覆纳米颗粒表面来控制它们的连接方式。相比之下，Yi 等人。开发了一种配体化学，当两个粒子连接在一起时，它会改变静电特性以限制随后的键合（参见 Gang 的观点）。粒子涂有互补的聚合物链，这些聚合物链经历酸碱中和反应。这种键合由柔性配体的长度控制，而结合粒子的排列由静电排斥控制，因此给出了两个参数来调整形成的组件的形状。科学，这个问题 p。第1369章 另见第 1305 具有类分子结构的纳米粒子簇是一类新兴的胶体材料。装饰有作为功能基团类似物的有吸引力的表面补丁的粒子用于组装胶体分子 (CM)；然而，高产率的片状纳米颗粒仍然是一个挑战。我们表明，对于用互补反应性聚合物覆盖的纳米粒子，化学计量反应导致均匀配体壳的重组和自限性纳米粒子键合，而胶体键之间的静电排斥控制着 CM 对称性。这种机制使高产 CM 生成及其在分层纳米结构中的可编程组织成为可能。我们的工作弥合了在原子水平上发生的共价键与在长度尺度上发生的胶体键之间的差距，两个数量级更大，并拓宽了纳米材料制造的方法。