Investigating FAM-N pulses for signal enhancement in MQMAS NMR of quadrupolar nuclei
نویسندگان
چکیده
منابع مشابه
Comparison of high-resolution solid-state NMR MQMAS and STMAS methods for half-integer quadrupolar nuclei.
Several different amplitude-modulated two-dimensional high-resolution methods, based on MQMAS and STMAS, are compared. They include 3QMAS, 5QMAS, DQ-STMAS, and DQF-STMAS experiments. A new method, called t1-split-STMAS, is also proposed for spin-3/2 nuclei. The comparison is performed in terms of isotropic resolution and spectral-width, efficiency, and sensitivity to magic-angle offset and spin...
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Selective reintroduction of anisotropic interactions such as the chemical shift anisotropy (CSA) and homonucler dipolar (HMD) coupling were implemented in a high-resolution NMR spectroscopy for half-integer quadrupolar nuclei. Rotary resonance recoupling (R(3)) combined with the multiple-quantum magic-angle spinning (MQMAS) in a three-dimensional (3D) experiment provides not only site-specific ...
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Ž . We report the first observation of residual dipolar couplings in magic-angle-spinning MAS and multiple quantum Ž . magic-angle-spinning MQMAS NMR spectra of half-integer quadrupolar nuclei. In particular, the fine spectral splittings observed in the B MAS spectrum of crystalline triethanolamine borate are attributed to the residual B–N dipolar coupling, which is not completely averaged by M...
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An approach for enhancing the NMR sensitivity of the central transition of spin-3r2 nuclei is presented. Through selective excitation of the satellite transitions using a fast 1808 phase alternating pulse train during magic-angle spinning a < : selectively excited state is prepared where the populations of all eigenstates m with the same sign of m are equal, resulting in an enhanced central msy...
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ژورنال
عنوان ژورنال: Solid State Nuclear Magnetic Resonance
سال: 2017
ISSN: 0926-2040
DOI: 10.1016/j.ssnmr.2017.01.001