Modulation of cross polarization in motionally averaged solids by variable angle spinning NMR
نویسندگان
چکیده
منابع مشابه
Double-quantum cross-polarization NMR in solids
Double-quantum NMR is a useful way to obtain spectra of quadrupolar nuclei ('D, "N, ...) in solids. This allows measurements of the chemical shifts for these nuclear spins. The theory of Hartmann-Hahn cross polarization between I = 1/2 and such S = 1 spins is discussed. Particular attention is drawn to the cross polarization of the double-quantum transition. The thermodynamics and the dynamics ...
متن کاملCross-polarization phenomena in the NMR of fast spinning solids subject to adiabatic sweeps.
Cross-polarization magic-angle spinning (CPMAS) experiments employing frequency-swept pulses are explored within the context of obtaining broadband signal enhancements for rare spin S = 1/2 nuclei at very high magnetic fields. These experiments employ adiabatic inversion pulses on the S-channel ((13)C) to cover a wide frequency offset range, while simultaneously applying conventional spin-locki...
متن کاملLow-power cross polarization in fast magic-angle spinning NMR experiments
0009-2614/$ see front matter 2008 Elsevier B.V. A doi:10.1016/j.cplett.2008.11.089 * Corresponding author. E-mail addresses: [email protected], [email protected] gmx.ch (B.H. Meier). We describe a low-power approach for heteronuclear cross-polarization (CP) at high magic-angle spinning (MAS) frequencies. It is based on second-order CP at the n = 0 Hartmann–Hahn condition. The mechanism for the polarizati...
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High-resolution solid state nTo NMR spectra of nTo-enficbed compounds were observed with multiple-quantum magic-angle-spinning (MQMAS) experiments. The resolution of the 170 MQMAS spectra is approximately 30to 150-fold higher than that found in conventional 170 MAS spectra, making it possible to detect crystallographically distinct oxygen sites. It is shown that into MQMAS studies are feasible ...
متن کاملOxygen - 17 Cross - Polarization NMR Spectroscopy of Inorganic Solids
We have obtained I70 nuclear magnetic resonance spectra of a variety of ‘70-labeled solids (Mg(OH)z, Ca(OH)*, boehmite (AlO(C talc (Mg3Si.,0,,(OH)2), (C6H,),SiOH, and amorphous Si02) using high-field static and “magioangle” sample spinning techniques, together with ‘H cross polarization and dipolar decoupling. Our results show that large cross-polarization enhancements can be obtained and that ...
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ژورنال
عنوان ژورنال: Chemical Physics Letters
سال: 2011
ISSN: 0009-2614
DOI: 10.1016/j.cplett.2011.04.043