Homonuclear dipolar decoupling under fast MAS: Resolution patterns and simple optimization strategy

1H Homonuclear dipolar decoupling using symmetry-based pulse sequences at ultra fast magic-angle spinning frequencies

“…Similar calculations have been done earlier for wPMLG x x mm for high MAS frequencies [15] and have been experimentally verified by Mao and Pruski for spinning frequencies m r > 10 kHz [31].…”

Tailored low-power cross-polarization under fast magic-angle spinning

“…MOD-CP supports a wide range of modulation frequencies (>36 kHz), which is advantageous for the study of biomolecules. As proton homonuclear decoupling techniques improve [63][64][65][66][67], MOD-CP could become useful for low-power hetero-nuclear correlation (HETCOR) experiments.…”

Solid-state nuclear magnetic resonance investigations of the nature, property, and activity of acid sites on solid catalysts

“…Narrowing by MAS is reached, if the correlation time of thermal mobility, t c , is large in comparison with the period of the sample spinning (t c bt rot ¼1/n rot ) [28]. In the case of low thermal motion, the residual line width Dn 1/2 MAS of MAS NMR central lines of solids is affected by homonuclear magnetic dipole-dipole interactions, which can be reduced either by further increasing the sample spinning frequency, n rot , or by the application of a multiple-pulse sequence [29,30]. The resolution of MAS NMR spectra may be affected by inhomogeneities of the external magnetic field, misadjustment of the magic angle, thermal motions and exchange processes [26], heteronuclear magnetic dipole-dipole interaction with quadrupole nuclei [31], anisotropy of the magnetic susceptibility [32], and, last but not least, a distribution of the isotropic chemical shift.…”