A simple pulse train, using 90° hard pulses, for selective excitation in high-resolution solid-state NMR

Initial Conditions for Carbon-13 MAS NMR 1D Exchange Involving Chemically Equivalent and Inequivalent Nuclei

“…Such a sequence is shown in Fig. 2c, where the preparation period includes a SELDOM pulse train (23), which saturates all ssb manifolds but one (Fig. 3c).…”

“…To do so we apply a selective excitation by a SELDOM pulse train (23) prior to the start of the ODESSA sequence, so that at the beginning of the mixing time only one ssb manifold is excited. During the mixing time, exchange between congruent, as well as between inequivalent, nuclei results in changes in the ssb intensities, all having the same phase as that of the originally excited ssb manifold.…”

Probing Structural and Motional Features of the C-Terminal Part of the Human Centrin 2/P17-XPC Microcrystalline Complex by Solid-State NMR Spectroscopy

“…Consequently, the Fourier transform of the time dependence leads to dipolar spectra ( Figure 12, right) featuring modified Pake doublets due to the oscillating heteronuclear polarization transfer, while proton spin-diffusion leads to an isolated central peak. 23,16,49 It is worth pointing out that the dipolar spectra shown in Figure 12 are largely dominated by the most rigid C−H and N−H pairs in the 44 residues of the four α-helices which have larger splittings than the 23 residues of the two EF-hand loops and the central linker, while the terminal parts do not appear to contribute significantly. Further experimental evidence shows that the rf-field inhomogeneity has a negligible effect on the dipolar splittings at accurately determined n = ±1 Hartmann− Hahn conditions (see Figure S5, Supporting Information, for a comparison of the lineshapes recorded with a fully packed rotor and with a small sample placed in the central part of the rotor).…”

High‐Performance Selective Excitation Pulses for Solid‐ and Liquid‐State NMR Spectroscopy

“…Hence, the signal is excited with the same phase it would have if excited by a hard 90 o y pulse. It is interesting that this mode of excitation is very different from the selective excitation provided by an alternative, hard pulse based technique called SELDOM, [40] which excites the full, undistorted sideband manifold.…”

“…This paradoxical situation stems partially from the expectation that these pulses will not function properly in the setting of magic angle spinning (MAS) experiments, and partially from the fact that, until recently, there was little need for this kind of pulses in solids. Simple Gaussian pulses, [38] DANTE pulse train, [3,39] and the SELDOM sequence [40] appeared sufficient in most cases. However, the situation has been rapidly changing recently.…”