Journal of the American Chemical Society | VOL. 129
Read

2D Multinuclear NMR, Hyperpolarized Xenon and Gas Storage in Organosilica Nanochannels with Crystalline Order in the Walls

Publication Date Jun 19, 2007

Abstract

The combination of 2D 1H-13C and 1H-29Si solid state NMR, hyperpolarized 129Xe NMR, synchrotron X-ray diffraction, together with adsorption measurements of vapors and gases for environmental and energetic relevance, was used to investigate the structure and the properties of periodic mesoporous hybrid p-phenylenesilica endowed with crystalline order in the walls. The interplay of 1H, 13C, and 29Si in the 2D heteronuclear correlation NMR measurements, together with the application of Lee-Goldburg homonuclear decoupling, revealed the spatial relationships (<5 angstroms) among various spin-active nuclei of the framework. Indeed, the through-space correlations in the 2D experiments evidenced, for the first time, the interfaces of the matrix walls with guest molecules confined in the nanochannels. Organic-inorganic and organic-organic heterogeneous interfaces between the matrix and the guests were identified. The open-pore structure and the easy accessibility of the nanochannels to the gas phase have been demonstrated by highly sensitive hyperpolarized (HP) xenon NMR, under extreme xenon dilution. Two-dimensional exchange experiments showed the exchange time to be as short as 2 ms. Through variable-temperature HP 129Xe NMR experiments we were able to achieve an unprecedented description of the nanochannel space and surface, a physisorption energy of 13.9 kJ mol-1, and the chemical shift value of xenon probing the internal surfaces. These results prompted us to measure the high storage capacity of the matrix towards benzene, hexaf...

Concepts

Hyperpolarized Xenon Hyperpolarized Hyperpolarized 129Xe NMR Crystalline Order High Degree Of Order Through-space Correlations Xenon NMR Hyperpolarized 129Xe 129Xe NMR Clean-energy Generation

Round-ups are the summaries of handpicked papers around trending topics published every week. These would enable you to scan through a collection of papers and decide if the paper is relevant to you before actually investing time into reading it.

Climate change Research Articles published between Nov 21, 2022 to Nov 27, 2022

R DiscoveryNov 28, 2022
R DiscoveryArticles Included:  2

No potential conflict of interest was reported by the authors. The conception and design of the study, acquisition of data, analysis and interpretatio...

Read More

Coronavirus Pandemic

You can also read COVID related content on R COVID-19

R ProductsCOVID-19

ONE PROBLEM . ONE PURPOSE . ONE PLACE

Creating the world’s largest AI-driven & human-curated collection of research, news, expert recommendations and educational resources on COVID-19

COVID-19 Dashboard

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on “as is” basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The Copyright Law.