Nanoparticles of metal-organic frameworks (nanoMOFs) boast superior properties compared to their bulk analogs, yet little is known about how common synthetic parameters dictate particle sizes. Here, we provide experimental evidence for the “seesaw” model of nanoMOF growth. Solution acidity, ligand excess, and reactant concentrations are decoupled and shown to form the key independent determinants of nanoMOF sizes, thereby validating the proposal that nanoMOFs arise from coupled equilibria involving ligand deprotonation and metal-ligand complexation. By achieving the first demonstration of a seesaw relationship between nanoMOF sizes and ligand excess, these results provide further proof of the model, as they required deliberate manipulation of relationships outlined by the model. Exploring the relative impacts of these parameters reveals that ligand excess has the greatest ability to decrease sizes, although low acidity and high concentrations can exhibit similar effects. As a complement to existing models of polymer formation and crystal growth, the seesaw model therefore offers a powerful tool for reliable control over nanoMOF sizes.

金属有机骨架（nanoMOF）的纳米粒子与其本体类似物相比具有优越的性能，但对于通用的合成参数如何决定粒径的了解却很少。在这里，我们为nanoMOF增长的“跷跷板”模型提供了实验证据。溶液的酸度，配体过量和反应物浓度被解耦，并显示出可形成nanoMOF尺寸的关键独立决定因素，从而验证了nanoMOFs是由涉及配体去质子化和金属-配体络合的耦合平衡产生的。通过首次证明nanoMOF大小与配体过量之间存在跷跷板关系，这些结果为模型提供了进一步的证明，因为它们需要对模型概述的关系进行有意的操纵。探索这些参数的相对影响表明，配体过量具有最大的减小尺寸的能力，尽管低酸度和高浓度可以表现出相似的效果。作为现有聚合物形成和晶体生长模型的补充，跷跷板模型为可靠控制nanoMOF尺寸提供了强大的工具。