Abstract
The fundamental idea was to find a chemically inert molecule, detectable by NMR and particularly sensitive to physical interactions with other species, which could be used as a probe to determine the properties of its environment. The 129Xe isotope is this ideal probe.
Chemical shifts and relaxation times of xenon are solely affected by intermolecular interactions and are exquisitely sensitive to the atom’s surrounding. This sensitivity to its environment means that the Xe nucleus can report on a wide variety of attributes of the physical systems in which it finds itself: gas, liquids, cages in zeolites, nanochannels in molecular solids, clathrates, proteins in solution, amorphous parts of solid polymers, elastomers, etc. It can be used also for imaging and gas diffusion measurements. By using optical polarization techniques the sensitivity of detection can be increased by several orders of magnitude and is particularly useful for several studies.
This talk will deal with various applications of Xe NMR.
About the speaker
The main contributions of Jacques Fraissard, Professor Emeritus at the University Pierre and Marie Curie - Paris, concern the fields of physical chemistry, solid surfaces, solid-gas interactions and as a consequence heterogeneous catalysis, and this by developing or applying in an original way various spectroscopic techniques.
Prof Fraissard received his PhD from Faculty of Sciences-Paris in 1961. As Research Associate at the Atomic Energy Center (1957-1961) he was the pioneer in the study by NMR of solid surfaces and adsorbed complexes, regardless of the nature of the catalyst: insulating, paramagnetic or metallic.
He joined the University Pierre and Marie Curie as Assistant Professor in 1963 and Professor in 1968. Then he created and managed during 40 years the National Laboratory of Surface Chemistry. His most important contribution since 1980 concerns zeolites, solid acid catalysts, Xe-NMR and more recently competitive diffusion of reactants in a catalyst bed. Professor Fraissard has written about 350 scientific publications in reviews and is the author or editor of 18 books. He organized and chaired 9 international congresses and 6 NATO ASI.
“Distinguished Professor” and Doctor Honoris Causa of several foreign universities, he received the awards of the French Chemical Society (1962) and of the French Academy of Sciences (1998), and the “Legion of Honour” (2004).
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