通过酸盐 (+gauche -gauche) 形成的两种3D铜酸盐基金属有机框架的溶剂和压力诱导的相变
Charl X Bezuidenhout1, Vincent J Smith1, Catharine Esterhuysen1
1Department of Chemistry and Polymer Science, University of Stellenbosch , Matieland 7602, South Africa.
Journal of the American Chemical Society
|April 1, 2017
概括
两个具有铜酸盐柱的柔性金属有机框架 (MOF) 在溶剂丢失时自发地改变相位,形成窄道. 一个MOF选择性地吸附二氧化碳,通过恢复到更宽的通道形式.
科学领域:
- 材料科学
- 晶体学
- 化学工程
背景情况:
- 金属有机框架 (MOF) 是具有可调节结构的高级多孔材料.
- 灵活的MOF可以在应对外部刺激时表现出结构变化.
- 了解框架动态对于设计特定应用的MOF至关重要.
研究的目的:
- 为了研究两种具有弹性支柱的异质铜 (II) 基MOF的相位行为.
- 描述结构变化及其对孔隙性的影响.
- 探索灵活的MOF的二氧化碳吸收特性和机制.
主要方法:
- 单晶X射线衍射 (SCXRD) 用于结构分析.
- 用于气体吸收研究的吸附同热量测量.
- 超临界二氧化碳用于隔离包含气体的结构.
- 用于解释机制的分子模型模拟.
主要成果:
- 两个MOF,Cu2 () 2 (bpa) 和Cu2 () 2 (bpp) 在溶剂丢失时自发变相为窄通道形式.
- 窄通道形式的溶剂可访问量显著减少.
- [Cu2 ((glu) 2 ((bpa)) 显示了 CO2 吸附等热体,表示在 CO2 压力下可逆转化为宽通道形式.
- SCXRD确定了框架通道内的二氧化碳分子位置.
- 分子建模阐明了相变机制和相关的能量.
结论:
- 灵活的支柱层MOF可以在去除溶剂时表现出显著的结构变化.
- [Cu2 ((glu) 2 ((bpa)) 的可逆相变允许有选择性的CO2吸收.
- 了解这些动态结构变化是设计用于气体分离和储存应用的MOF的关键.
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