Dynamic-angle spinning of quadrupolar nuclei

Scalar operators in solid-state NMR

“…{2.12) and (2.13). These solutions coincides with the trajectories used in dynamic angle spinning (DAS) [76,78], double rotation (DOR) [72,104], and dynamic angle hopping (DAH) , which are used to eliminate the second order line broadenings of the central transitions in spin half integer quadrupolar nuclei. The similarity arises because the second order line broadenings are detennined by both the second and the fourth rank spatial tensors of the first order average Hamiltonian in the rotating frame.…”

“…Unfortunately, the numerical simulations have not yet been accomplished and are left for future work. [56,57,58], dynamic angle spinning (DAS) [78,76], double rotation (DOR) [72,104]' and multiple pulse (MP) [114]. The principle involved in these methods is the coherently motional averaging under which the orientation dependence of the resonance frequency can be completely or partially removed, and the NMR spectra contain only the isotr<;>pic chemical shifts.…”

“…On the first cone spins will evolve for a time tl while on the second cone they evolve for a . We call this trajectory dynamic angle spinning (DAS) [76] for zero field NMR in high field, and, as in DAH, yields the coupling constants 8). scaled down by a factor of five (that is, U = ~).…”

“…These approaches are called dynamic angle spinning (DAS) [73,76] and double rotation (DOR) [72,104,78].…”

Heteronuclear spin decoupling in solid-state NMR under magic-angle sample spinning

“…Only the second-rank tensor contribution is averaged out by 11 the MAS rotation. However, by using different spatial averaging techniques such as dynamic-angle spinning (DAS) or double rotation (DOR) (32), (33), (34) it would be possible to average out both the second-rank and the fourth-rank parts of the cross term simultaneously, leaving only the isotropic (zeroth-rank tensor) part unchanged.…”