Characterization of the Metal-Organic Framework Compound Cu3(benzene 1,3,5-tricarboxylate)2 by Means of 129Xe Nuclear Magnetic and Electron Paramagnetic Resonance Spec
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- 作者：Winfried Bö ; hlmann ; Andreas Pö ; ppl ; Michal Sabo ; Stefan Kaskel
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：October 19, 2006
- 年：2006
- 卷：110
- 期：41
- 页码：20177 - 20181
- 全文大小：98K
- 年卷期：v.110,no.41(October 19, 2006)
- ISSN：1520-5207
文摘
129Xe NMR measurements of adsorbed xenon are shown for the first time to be a suitable tool to characterizethe porosity and the properties of the metal-organic framework Cu3(BTC)2(H2O)3 (BTC = benzene 1,3,5-tricarboxylate). The NMR experiments are performed at room temperature and over a wide range of xenonpressure and on two different synthesized Cu3(BTC)2 samples. 129Xe NMR results reveal that in dependenceon the kind of the synthesis pathway either one or two signals are observed which can be attributed to twokinds of fast exchange of xenon atoms in two pores with different pore sizes. Coadsorption experiments ofxenon and ethylene demonstrate that the xenon atoms prefer to fill the greater pores of the material becausethe smaller pores are occupied with residual molecules from the synthesis procedure and additionally adsorbedethylene. Besides the NMR experiments a series of electron paramagnetic resonance (EPR) measurementsare performed to estimate the state of copper having a strong influence on the chemical shift of the adsorbedxenon. The EPR experiments demonstrate that spin exchange between the interconnected copper dimers istaking place across the BTC linker molecules in the Cu3(BTC)2 framework.