Taddei Marco, van Bokhoven Jeroen A, Ranocchiari Marco
Laboratory for Catalysis and Sustainable Chemistry, Paul Scherrer Institute, 5232 Villigen-PSI, Villigen, Switzerland.
Institute for Chemical and Bioengineering, ETH Zürich, Vladimir Prelog Weg 1, 8093 Zürich, Switzerland.
Inorg Chem. 2020 Jun 1;59(11):7860-7868. doi: 10.1021/acs.inorgchem.0c00991. Epub 2020 May 14.
We recently discovered that aging a solution of zirconium(IV) tetrachloride (ZrCl) in ,-dimethylformamide (DMF) in the presence of water, followed by the addition of a terephthalic acid linker, reduces the crystallite size of the metal-organic framework UiO-66 ( , , 6411-6414). In an effort to shed light on the nature of the aging effect and on its relationship with the crystallite size of UiO-66, we report here the isolation and structural characterization of a microcrystalline zirconium-based compound of the formula [ZrCl(OH)(DMF)]Cl, which is formed during the aging process. The Zr(IV) ions are coordinated by hydroxide, DMF, and chloride to produce a one-dimensional polymer. Thanks to the presence of two -OH groups per zirconium atom, [ZrCl(OH)(DMF)]Cl is a suitable precursor for the synthesis of UiO-66 in dry DMF, affording a product having a smaller crystallite size than that obtained from a reaction mixture having the same chemical composition but using ZrCl as the Zr(IV) source. By starting from ZrCl and generating [ZrCl(OH)(DMF)]Cl in situ in solution through aging, we obtained smaller crystallites as the aging time increased, proving that [ZrCl(OH)(DMF)]Cl plays a role in the aging process. The possible role of [ZrCl(OH)(DMF)]Cl in the crystallization mechanism of UiO-66 is also discussed, with emphasis on its relationship with the amount of water in the reaction mixture.
我们最近发现，在水存在的情况下，将四氯化锆（ZrCl₄）的溶液在N，N-二甲基甲酰胺（DMF）中老化，然后加入对苯二甲酸连接体，会减小金属有机框架UiO-66的微晶尺寸（参考文献6411 - 6414）。为了阐明老化效应的本质及其与UiO-66微晶尺寸的关系，我们在此报告了一种式为[ZrCl(OH)(DMF)]Cl的微晶锆基化合物的分离和结构表征，该化合物是在老化过程中形成的。Zr(IV)离子由氢氧化物、DMF和氯离子配位，形成一维聚合物。由于每个锆原子存在两个 -OH基团，[ZrCl(OH)(DMF)]Cl是在干燥DMF中合成UiO-66的合适前体，得到的产物微晶尺寸比使用ZrCl₄作为Zr(IV)源、具有相同化学成分的反应混合物所得到的产物更小。通过从ZrCl₄开始，并通过老化在溶液中原位生成[ZrCl(OH)(DMF)]Cl，随着老化时间增加，我们得到了更小的微晶，证明[ZrCl(OH)(DMF)]Cl在老化过程中起作用。还讨论了[ZrCl(OH)(DMF)]Cl在UiO-66结晶机制中的可能作用，重点是其与反应混合物中水含量的关系。
