压力-温度空间中的金属-有机框架的丰富多态性
Remo N Widmer1, Giulio I Lampronti1, Siwar Chibani2
1Department of Earth Sciences , University of Cambridge , Downing Street , Cambridge CB2 3EQ , U.K.
Journal of the American Chemical Society
|May 24, 2019
概括
高压和高温揭示了ZIF-4金属有机框架的四个新阶段. 这些发现突显了ZIF材料在极端条件下的复杂相位行为.
科学领域:
- 材料科学
- 晶体学
- 化学学
背景情况:
- 金属有机框架 (MOF) 具有不同的结构和特性.
- 了解极端条件下的MOF相稳定性对于它们的应用至关重要.
- ZIF-4 (Zn(imidazolate) 2是一种经过充分研究的MOF,具有各种应用的潜力.
研究的目的:
- 在高压和高温度下研究ZIF-4的相稳定性和多态性.
- 为ZIF-4构建一个压力-温度相位图.
- 为了阐明ZIF-4新型高压,高温相的晶体结构.
主要方法:
- 在现场粉末X射线衍射 (PXRD) 用于研究ZIF-4.
- 在高压 (高达8GPa) 和高温 (高达600°C) 的同时进行了实验.
- 用密度函数理论 (DFT) 的计算来评估新阶段的总能量.
主要成果:
- 为ZIF-4建立了一个复杂的压力-温度相图,揭示了四个新的高压-高温相.
- 使用PXRD数据解决了ZIF-4-cp-II和ZIF-hPT-II两个新阶段的晶体结构.
- 在极端条件下,ZIF-hPT-II与Cd{\ imidazolate}2和Hg{\ imidazolate}2具有异构的稳定性.
结论:
- 与ZIF-62等相关ZIF相比,该研究显示ZIF-4的相位行为显著复杂.
- 这些发现证明了高压和高温在探索复杂的MOF能源环境中的实用性.
- 发现的相及其特性为MOF的结构多样性和稳定性提供了新的见解.
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