| Autor: |
Iuga, Adriana, Iuga, Dinu, Cross, Albert R., Gerken, Michael, Hazendonk, Paul |
| Předmět: |
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| Zdroj: |
Journal of Chemical Physics; 2/7/2007, Vol. 126 Issue 5, p054305, 10p, 10 Graphs |
| Abstrakt: |
A method is introduced to select the signal from a spin-1/2 nucleus I specifically bound to another spin-1/2 nucleus S for solid-state magic angle spinning nuclear magnetic resonance (NMR) spectroscopy via correlation through the heteronuclear J coupling. This experiment is analogous to the bilinear rotation decoupling (BIRD) sequence in liquid-state NMR spectroscopy which selects for signals from 1H directly bound to 13C. The spin dynamics of this modified BIRD experiment is described using the product-operator formalism, where experimental considerations such as rotor synchronization and the effect of large chemical shielding anisotropies on I and S are discussed. Two experiments are proposed that accommodate large chemical shielding anisotropies on S: (1) by stepping the inversion pulse frequency through the entire S spectral range or (2) by adiabatically inverting the S spins. Both these experiments are shown to successfully select the signal of 19F bound to 129Xe in XeF+ salts, removing the contributions from isotopomers containing non-spin-1/2 Xe isotopes. The feasibility in obtaining isotope-selective 19F spectra of inorganic fluoride compounds is discussed, and further modifications are proposed to expand the application to other chemical systems. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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