Al Isawi Wisam A, Zeller Matthias, Mezei Gellert
Department of Chemistry, Western Michigan University, Kalamazoo, Michigan 49008, United States.
Department of Chemistry, Purdue University, West Lafayette, Indiana 47907, United States.
ACS Omega. 2024 Oct 18;9(43):43986-43997. doi: 10.1021/acsomega.4c08535. eCollection 2024 Oct 29.
While the fact that HF etches glass is rather common chemical knowledge, the reaction of fluoride ions in an organic solvent with glassware under alkaline conditions has not yet been documented. It becomes apparent that, in general, whenever any fluorine-containing material is handled in silicon-based glassware, the possible presence of SiF should be considered regardless of the pH of the reaction medium. Subsequent to the initial, inadvertent synthesis by the reaction of CuF with laboratory glassware, hexafluorosilicate-entrapping supramolecular assemblies (nanojars) of the formula [SiF⊂{-Cu(μ-OH)(μ-pz)} ] ( ; = 28, 30, 32, 34) were rationally prepared by the reaction of Cu with pyrazole (Hpz) in the presence of a base and SiF ions or by combining with HSiF or HF. This work demonstrates that nanojars are excellent anion-binding agents not only for trigonal planar/pyramidal or tetrahedral anions but also for larger, octahedral anions, which are bound exclusively by charge-assisted hydrogen bonds. The SiF anion guest is preferentially bound by a larger Cu host, whereas CO favors a smaller Cu nanojar. The mixture was characterized by electrospray ionization mass spectrometry as well as variable-temperature, paramagnetic H and F NMR spectroscopy in solution, complemented by single-crystal X-ray diffraction studies in the solid state, which reveal the unprecedented structure of a Cu nanojar (where Cu, Cu, and Cu are the component Cu metallamacrocycles of the Cu nanojar).
虽然氢氟酸蚀刻玻璃这一事实是相当常见的化学知识，但在碱性条件下有机溶剂中的氟离子与玻璃器皿的反应尚未见文献记载。显然，一般来说，只要在硅基玻璃器皿中处理任何含氟材料，无论反应介质的pH值如何，都应考虑可能存在的SiF。在最初因CuF与实验室玻璃器皿反应而意外合成之后，通过在碱和SiF离子存在下Cu与吡唑（Hpz）反应，或通过将与HSiF或HF混合，合理制备了式为[SiF⊂{-Cu(μ-OH)(μ-pz)} ]（ ； = 28、30、32、34）的包封六氟硅酸盐的超分子组装体（纳米罐）。这项工作表明，纳米罐不仅是三角平面/金字塔形或四面体阴离子的优秀阴离子结合剂，也是更大的八面体阴离子的优秀阴离子结合剂，这些阴离子仅通过电荷辅助氢键结合。SiF阴离子客体优先被较大的Cu主体结合，而CO则倾向于较小的Cu纳米罐。通过电喷雾电离质谱以及溶液中的变温顺磁H和F NMR光谱对混合物进行了表征，并辅以固态单晶X射线衍射研究，这些研究揭示了Cu纳米罐前所未有的结构（其中Cu、Cu和Cu是Cu纳米罐的组成Cu金属大环）。
