%0 Journal Article %J Angewandte Chemie-International Edition %D 2007 %T Para-hydrogen-enhanced hyperpolarized gas-phase magnetic resonance imaging %A Bouchard, L. S. %A Kovtunov, K. V. %A Burt, S. R. %A Anwar, M. S. %A Koptyug, I. V. %A Sagdeev, R. Z. %A Pines, A. %K he-3 %B Angewandte Chemie-International Edition %V 46 %P 4064-4068 %@ 1433-7851 %G English %U ://WOS:000246981900008 %N 22 %M WOS:000246981900008 %! Para-hydrogen-enhanced hyperpolarized gas-phase magnetic resonance imaging %R Doi 10.1002/Anie.200700830 %0 Journal Article %J Journal of the American Chemical Society %D 2007 %T Para-hydrogen-induced polarization in heterogeneous hydrogenation reactions %A Koptyug, I. V. %A Kovtunov, K. V. %A Burt, S. R. %A Anwar, M. S. %A Hilty, C. %A Han, S. I. %A Pines, A. %A Sagdeev, R. Z. %K alignment %X

We demonstrate the creation and observation of para-hydrogen-induced polarization in heterogeneous hydrogenation reactions. Wilkinson's catalyst, RhCl(PPh3)(3), supported on either modified silica gel or a polymer, is shown to hydrogenate styrene into ethylbenzene and to produce enhanced spin polarizations, observed through NMR, when the reaction was performed with H-2 gas enriched in the para spin isomer. Furthermore, gaseous phase para-hydrogenation of propylene to propane with two catalysts, the Wilkinson's catalyst supported on modified silica gel and Rh(cod)(sulfos) (cod = cycloocta-1,5-diene; sulfos = -O3S(C6H4)CH2C(CH2PPh2)(3)) supported on silica gel, demonstrates heterogeneous catalytic conversion resulting in large spin polarizations. These experiments serve as a direct verification of the mechanism of heterogeneous hydrogenation reactions involving immobilized metal complexes and can be potentially developed into a practical tool for producing catalyst-free fluids with highly polarized nuclear spins for a broad range of hyperpolarized NMR and MRI applications.

%B Journal of the American Chemical Society %V 129 %P 5580-5586 %8 May 2 %@ 0002-7863 %G English %U ://WOS:000245946400064 %N 17 %M WOS:000245946400064 %! para-hydrogen-induced polarization in heterogeneous hydrogenation reactions %R Doi 10.1021/Ja068653o