Hyperpolarized xenon

Moudrakovski, I.L. Sanchez, A.A. Ratcliffe, C.I. Ripmeester, J.A. (2001). Nucleation and Growth of Hydrates on Ice Surfaces New Insights from 129Xe NMR Experiments with Hyperpolarized Xenon. J. Phys. Chem. B, 105, 12338-12347. 

Imaging void space with hyperpolarized xenon... 

Some less frequently encountered nuclides, such as 57Fe and 59Co, have chemical shift ranges of more than 10,000 ppm, hence encompass a very large frequency range in spite of smaller magnetogyric ratios. The chemical shift of monatomic 129Xe gas is very sensitive to its environment, and hyperpolarized xenon (Section 2.5) can be used to probe adsorption sites in solids. 

The xenon atom can therefore be used as a delicate probe to determine the number of surrounding water molecules and their orientations. These results demonstrate the sensitivity of the easily polarizable xenon electronic structure to the electrostatic properties of its surrounding and the great potential for achieving accurate interpretations of magnetic resonance parameters from imaging experiments with hyperpolarized xenon. 

Applications of solid state NMR are included in other topical sections below, such as polymer and hyperpolarized xenon. 

Chemical Shift. The relationship between pore size and chemical shifts for many controlled pore glasses has been established by the exploration of hyperpolarized xenon gas in the porous solids. A number of recent developments in Xe NMR speetroscopy and microimaging were reported with direct applications to the study of mesopore space in solids (37 references)." Experiments illustrated include the rapid eharaeterization of the void space in porous solids, including the in situ proeesses such as diffusion and dehydration, and imaging with chemical shift resolution. Chemieal shift imaging with continuously flowing hyper-polarized xenon was applied to the characterization of materials." ... 

Sozzani. P. Comotti. 4. Simonutti, R. Meersmann, T. Logan, J. W. A porous crystalline molecular solid explored by hyperpolarized xenon. Angew. Chem.. Int. Ed. 2002. 39. 2695-2699. 

The application of Xe NMR can benefit from the use of hyperpolarized xenon. Xe relaxation time is extremely long, and the nonequilibrium states in which the difference in populations between the two spin states is much larger than the natural one can be prepared and transferred to the NMR tube. The NMR sensitivity is proportional to polarization and can be increased by three to five orders of magnitude. In optical hyperpolarization, circularly polarized light, in which photons are polarized, is used to increase the polarization of xenon atoms through a complex process, in which polarization is transferred first to rubidium atoms. ... 

R 283 Anonymous, Development of Hyperpolarized Xenon Gas Generation Apparatus , Kogyo Zairyo, 2004,52,86... 

Duewel M, Vogel N, Weiss CK, Landfester K, Spiess H-W, Munnemann K. Online monitoring of styrene polymerization in miniemulsion by hyperpolarized Xenon NMR spectroscopy. Macromolecules 2012 45 1839-1846. 

Several more recent approaches are based on the creation of very high polarizations, for example dynamic nuclear polarization [11], para-hydrogen in two-spin systems [12], and hyperpolarized xenon [13]. In addition, there are other spincooling methods, based on general unitary transformations [7] and on (closely related) data compression methods in closed systems [8]. 

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