Nuclear Quadrupole Effects

Townes, C. H. and B. P. Dailey Nuclear Quadrupole Effects and Electronic Structure of Molecules in the Solid State. J. Chem. Phys. 20, 35 (1952). 

Investigations of the influence of lattice defects on NMR and the accompanying nuclear quadrupole effects have been studied in many papers (see references 125,161))... 

Townes CH, Dailey BP (1952) Nuclear quadrupole effects and electronic structure of molecules in the solid state. J Chem Phys 20 35... 

Townes CH and Dailey BP (1949) Determination of electronic structure of molecules from nuclear quadrupole effects. Journal of Chemical Physics 17 782-796. 

M. H. Cohen and F. Reif, Nuclear quadrupole effects in nuclear magnetic resonance. Solid State Phys. 5, 321-438 (1957). 

From accurate measurements of the Stark effect when electrostatic fields are applied, information regarding the electron distribution is obtained. Further Information on this point is obtained from nuclear quadrupole coupling effects and Zeeman effects (74PMH(6)53). 

The reduction of the C— Br and C—1 group moments from 1.10 and 0.90 in bromo- and iodo-benzene to about 0.80 and 0.50 in 2-bromo- and 2-iodo-thiophene has been ascribed to the larger weight of resonance forms such as (8) and (9) in the thiophene series. The chlorine, nuclear, quadrupole, resonance frequencies of chloro-substituted thiophenes are much higher than those of the corresponding benzene derivatives. This has been ascribed to a relayed inductive effect originating in the polarity of the C—S o-bond in thiophenes. The refractive indices, densities, and surface tension of thiophene, alkyl- and halo-thiophenes, and of some other derivatives have been... 

Lantto, P. and Vaara, J. (2006) Calculations of nuclear quadrupole coupling in noble gas-noble metal fluorides Interplay of relativistic and electron correlation effects. Journal of Chemical Physics, 125, 174315-1-174315-7. 

The nuclear Zeeman effect is not a very strong interaction as compared to electric quadrupole splitting because of the relatively weak nuclear magneton. A field of B... 

The spectra discussed in Chapter 4 were analyzed by neglecting the effects of nuclear quadrupole coupling on the nuclear hyperfine structure. Presented here is the way such effects may be incorporated into the spectra using perturbation theory. 

There have been numerous applications of continuum models to equilibria and reactions in solution surveys of these and extensive listings are provided by Cramer and Truhlar.16 Other studies have focused upon the effects of solvents upon solute molecular properties, such as electronic and vibrational spectra,16 dipole moments, nuclear quadrupole and spin-spin coupling constants and circular dichroism.12... 

Wehrli, W. Ansamycins Chemistry, Biosynthesis and Biological Activity. 72, 21-49 (1977). Weiss, A. Crystal Field Effects in Nuclear Quadrupole Resonance. 30, 1-76 (1972). 

Chemists pay much less attention to the NMR relaxation rates than to the coupling constants and chemical shifts. From the point of view of the NMR spectroscopist, however, the relaxation characteristics are far more basic, and may mean the difference between the observation or not of a signal. For the quadrupolar nucleides such as 14N the relaxation characteristics are dominated by the quadrupole relaxation. This is shown by the absence of any nuclear Overhauser effect for the 14N ammonium ion despite its high symmetry, which ensures that the quadrupole relaxation is minimized. Relaxation properties are governed by motional characteristics normally represented by a correlation time, or several translational, overall rotational and internal rotational, and thus are very different for solids, liquids and solutions. 

Nuclear quadrupole resonance, 8 257-282 effect of cations on, 8 273-275 metal-ligand bond study by, 8 264-273 quadrupole coupling constant and, 8 250-260... 

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