Study of xenon binding in cryptophane-A using laser-induced NMR polarization enhancement
- Univ. Libre de Bruxelles (Belgium). Lab. de Chimie Organique E.P.
- Univ. of California, Berkeley, CA (United States). Dept. of Chemistry
Xenon is chemically inert, yet exhibits NMR parameters that are highly sensitive to its chemical environment. Considerable work has therefore capitalized on the utility of {sup 129}Xe (I = 1/2) as a magnetic resonance probe of molecules, materials, and biological systems. In solution, spin-polarization transfer between laser-polarized xenon and the hydrogen nuclei of nearby molecules leads to signal enhancements in the resolved {sup 1}H NMR spectrum, offering new opportunities for probing the chemical environment of xenon atoms. Following binding of laser-polarized xenon to molecules of cryptophane-A, selective enhancements of the {sup 1}H NMR signals were observed. A theoretical framework for the interpretation of such experimental results is provided, and the spin polarization-induced nuclear Overhauser effects are shown to yield information about the molecular environment of xenon. The observed selective {sup 1}H enhancements allowed xenon-proton internuclear distances to be estimated. These distances reveal structural characteristics of the complex, including the preferred molecular conformations adopted by cryptophane-A upon binding of xenon.
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 682025
- Journal Information:
- Journal of the American Chemical Society, Vol. 121, Issue 14; Other Information: PBD: 14 Apr 1999
- Country of Publication:
- United States
- Language:
- English
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