Postsynthetic strategies for modifying metal-organic frameworks (MOFs) have proven to be an incredibly powerful approach for expanding the scope and functionality of these materials. Previously, we reported on the postsynthetic exchange (PSE) of metal ions and ligands in the University of Oslo (UiO) series of MOFs. Detailed characterization by several analytical methods, most notably inductively coupled plasma mass spectrometry and transmission electron microscopy reveal that metal ion deposition on the surface of these MOFs occurs in the form of nanoscale metal oxides, rather than yielding exchanged metal sites within the MOFs, as was previously reported. By contrast, these combined analytical methods do confirm that ligand-based PSE can occur in these MOFs. These findings provide new insight into the postsynthetic manipulation of MOF materials, highlight the importance of rigorously characterizing these materials to correctly assign their composition and structure, and provide a new route to making hybrid solids with a MOF@metal oxide architecture.

中文翻译：

---

透射电子显微镜揭示金属氧化物涂层在金属有机框架上的沉积

用于修饰金属有机框架 (MOF) 的合成后策略已被证明是一种非常强大的方法，可以扩展这些材料的范围和功能。此前，我们报道了奥斯陆大学 (UiO) 系列 MOF 中金属离子和配体的合成后交换 (PSE)。通过几种分析方法的详细表征，最显着的是电感耦合等离子体质谱和透射电子显微镜显示，这些 MOF 表面上的金属离子沉积以纳米级金属氧化物的形式发生，而不是在 MOF 内产生交换的金属位点，正如之前报道过。相比之下，这些组合分析方法确实证实了基于配体的 PSE 可以发生在这些 MOF 中。这些发现为 MOF 材料的后合成操作提供了新的见解，