Shielding of nuclei in NMR

Sex hormones, 1040—1042, 1044 Shared-electron pair bond. See Covalent bond Shielding of nuclei in NMR spectroscopy, 493—495. See also Chemical shift Sickle-cell anemia, 1089—1090, 1100 Sigma bond, 32... 

The results of research on the NMR spectra of elements with different isotopic composition have been reported. (95) The particular interest of these investigations lies in the possibility of applying perturbation theory to account for the contribution of vibrational states to the shielding of nuclei. (96, 97) In addition, the measurement of nuclear g factors of isotopic pairs, with great accuracy, is required for evaluating small hyperfine structure anomalies. (39,98)... 

In the opening chapter, An Introduction to Solution, Solid-State, and Imaging NMR Spectroscopy Leslie Butler (Louisiana State University) introduces the fundamental structure parameters in the NMR experiment through a discussion on solution state H NMR. The shielding of nuclei by core and valence electrons, gives rise to those structure-pregnant numbers called chemical shifts, d, that have been accrued and correlated since the earliest days of NMR. Scalar coupling,... 

The shielding of nuclei by y-substituents in a gauche arrangement (y-gauche effect) enables us to both complete and simplify the conformational connection between the microstructures and NMR spectra of polymers. 

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