scholarly journals What Are the Relative Intensities of the Components of NMR Spectral Multiplets from Quadrupolar Nuclei in Uniformly Anisotropic Media?

2021 ◽  
Vol 2021 ◽  
pp. 1-25
Author(s):  
Stuart J. Elliott ◽  
Philip W. Kuchel
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Quantum Mechanics ◽  
Magnetic Resonance ◽  
Nuclear Spin ◽  
Quadrupolar Nuclei ◽  
Partial Alignment ◽  
Spin Quantum ◽  
Guest Species ◽  
Spin Quantum Number ◽  
Nuclear Magnetic Resonance Spectra

Stretched hydrogels make uniformly anisotropic environments for quadrupolar nuclei such as 2H, 23Na, and 133Cs. Such surroundings cause the partial alignment of nuclear spin bearing ions and molecules that is sufficiently pronounced to alter the nuclear magnetic resonance spectra of the guest species. In most cases, resonance splittings are directly related to the spin quantum number I. The relative intensities of the components of the resonance multiplets can be inferred from basic quantum mechanics.

Biological and model membranes studied by nuclear magnetic resonance of spin one half nuclei

1977 ◽  
Vol 10 (1) ◽  
pp. 67-96 ◽  
Author(s):  
Håkan Wennerström ◽  
Göran Lindblom
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Membrane Systems ◽  
Inherent Anisotropy ◽  
Dipole Interactions ◽  
Spin Quantum ◽  
Spin Quantum Number ◽  
Nuclear Magnetic Resonance Spectra ◽  
Quadrupole Coupling ◽  
Nuclear Magnetic

There is an inherent anisotropy in biological and model membrane systems and this anisotropy has a profound influence on the nuclear magnetic resonance spectra of such systems. For nuclei with a quadrupole moment the quadrupole coupling usually dominates the NMR spectrum, while for nuclei with spin quantum number I = ½ dipolar couplings provides the most important effects. The quadrupole coupling only affects isolated spins and usually gives rise to simple spectra. The dipole interactions on the other hand couple several spins. In a lipid bilayer with a multitude of spin-½ nuclei these couplings can give rise to complicated manybody effects. Thus the interpretation of the NMR spectra of membrane systems poses problems but at the same time there is a lot of information to be gained.

Carbon-13 nuclear magnetic resonance studies of (Z)-5-fluoro-2-methyl-1-{[p-(methylsulfinyl)phenyl] methylene}-1H-indene-3-acetic acid (sulindac) and some related compounds

1978 ◽  
Vol 56 (16) ◽  
pp. 2129-2133 ◽  
Author(s):  
Alan Wilmot Douglas
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Acetic Acid ◽  
Magnetic Resonance ◽  
Nuclear Spin ◽  
Substituent Effects ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Nuclear Magnetic Resonance Spectra ◽  
Spin Coupling Constants ◽  
Nuclear Magnetic

Carbon-13 nuclear magnetic resonance spectra have been obtained and fully assignee for a number of 2-methyl-1-{[p-(methylthio) or -(methylsulfinyl}phenyl]methylene}-1H-indene-3- acetic acid derivatives, including the potent anti-inflammatory compound sulindac, 1Z. Paired E and Z isomers were studied along with the sulindac sodium salt and ethyl ester in the Z series. Variations in steric crowding in E vs. Z isomers produce chemical shift effects which alternate with the number of intervening bonds. Fluorine substituent effects and 19F nuclear spin coupling to 13C nuclei, second-order features in off-resonance proton-decoupled spectra, and values of long-range 13CH nuclear spin coupling constants have been employed in making a complete set of assignments.

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