连接器替代剂控制金属有机框架中的热力学稳定性
Novendra Novendra1, Joseph M Marrett2, Athanassios D Katsenis2
1Peter A. Rock Thermochemistry Laboratory and NEAT ORU, University of California Davis, One Shields Avenue, Davis, California 95616, United States.
Journal of the American Chemical Society
|December 16, 2020
概括
我们发现,在金属有机框架 (MOF) 中更改连接器会对其稳定性产生重大影响. 这一发现提供了一种通过了解链接器化学来设计具有所需属性的MOF的新方法.
科学领域:
- 材料科学
- 化学学
- 计算化学
背景情况:
- 金属有机框架 (MOF) 是具有可调节性质的高级多孔材料.
- 了解影响MOF热力学稳定的因素对于其应用至关重要.
- 岩性伊米达酸框架 (ZIF) 是MOF的一个子类,具有多种潜在用途.
研究的目的:
- 系统地研究连接器功能化和MOF的热力学稳定性之间的关系.
- 建立链接器结构和MOF形成度之间的可量化的联系.
- 为合理设计具有定制稳定的MOF提供见解.
主要方法:
- 实验合成和表征八种同结构的石化模酸框架 (ZIF).
- 通过形成度测量进行热力学稳定性评估.
- 密度函数理论 (DFT) 计算以建模和验证能量.
- 链接替代物特性 (例如,哈梅特 σ 常数) 和 MOF 稳定性之间的相关性分析.
主要成果:
- 在ZIF模型集中观察到形成度的显著变化 (高达30kJ·mol-1).
- 观察到的热力学变化与可访问的链接替代物性质有线相关.
- 密度函数理论 (DFT) 准确地复制了实验热力学数据.
- 尽管稳定性发生了显著变化,但摩尔体积的变化很小.
结论:
- 连接器功能化是MOF热力学稳定性的关键决定因素.
- 链接替代物特性和MOF能量之间存在可预测的关系.
- 这项研究为设计和调整通过链接器修改的MOF稳定性提供了定量框架.
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