Carbonyl Carbon and Nitrogen Chemical Shift Tensors of the Amide Fragment of Acetanilide and N-Methylacetanilide

Methods for the Determination of Torsion Angle Restraints in Biomacromolecules

“…The bases for these simulations are Eqs. (25) The orientation and size of the CSA tensor are known from solid-state NMR studies both for amides (Hartzell et al, 1987;Lumsden et al, 1994) and for aliphatic carbons (Janes et al, 1983) and can be used for these studies in high-resolution NMR. A review of investigations of CSA tensors of all kinds of heteronuclei that have been determined by means of solid-state NMR is given by Duncan (1990).…”

“…(31), the Fourier transformation including an apodization function w(t) will yield the following line shape F µv (ω) for the multiplet line I µv Figure 51. Orientation of the 15 N CSA tensor in a peptide according to Lumsden et al (1994). σ 11 and σ 33 are oriented in the peptide plane, where σ 33 is rotated about ca.…”

Polymorphism of N,N′′‐Diacetylbiuret Studied by Solid‐State 13C and 15N NMR Spectroscopy, DFT Calculations, and X‐ray Diffraction

“…The CSA tensors are comparable to those of acetanilide [45] and the fiber-modification of gluconamide [46] with respect to the isotropic (d iso = 105-127 ppm compared with 137 and 124 ppm, respectively) and the anisotropic chemical shifts (d aniso = 110-115 ppm compared with 108 and 115 ppm, respectively). Only the asymmetry parameters are considerably larger for DAB, with h = 0.4 compared with 0.11 and 0.17, respectively.…”

REDOR with Adiabatic Dephasing Pulses

“…11 ϭ 90 ppm, 22 ϭ 175 ppm, and 33 ϭ 248 ppm (27). For comparison we have also given the response following a normal 180°RF pulse of 8-s duration.…”

“…Other relevant experimental parameters are given in the figure captions. A ( 13 C, 15 N) labeled acetanilide sample, prepared as described (27), was packed so as to fill the full rotor volume and was employed in our investigations. An adiabatic inversion sequence with the amplitude and frequency modulation functions given above and having a constant adiabaticity factor of 4 has been employed uniformly in our work.…”