Nuclear quadrupole coupling constants deuteron

Relaxation and self-diffusion techniques in solution are widely used to study hydrogen-bonded systems. The nuclear quadrupole coupling constant (NQCC) presents a sensitive probe for the strength of hydrogen bonding. Unfortunately in the liquid phase this property cannot be measured in a direct way. Two new indirect methods are now presented for determining NQCC in H-bonded liquids. Ferris and Farrar showed that for the OD deuteron of ethanol the DQCC is related to the chemical shift of the hydroxy proton by a linear equation. Thus the straightforward measurement of the chemical shift... 

Deuterium has a nuclear spin of unity (/ = 1) and a small nuclear quadrupole moment, Q = 2.7965 X 10"27 cm2.35 In compounds containing deuterium, the molecular environment of the deuterium nucleus usually has a symmetry less than Tdeuteron quadrupole coupling constant is non-zero. However, its value is quite small because both the nuclear quadrupole moment and the electric field gradient have small values. The reported values of e2qQ/h for deuterium are always less than 400 kHz. 

The general cases of symmetric and asymmetric tops have been reviewed.56 For deuterium, the nuclear quadrupole interaction is small and the hyperfine structure is not always resolved, so that the deuteron quadrupole coupling constant must be obtained by curve-fitting. The accuracy of the data diminishes as the size and the asymmetry of the molecule increases. 

Still another source of information is nuclear quadrupole resonance spectroscopy. Waddington and Smith (96a) have used the C1 resonance to obtain evidence of genuine symmetry in the ions ClHCl- and C1DC1 in a salt known (97) to have a Type A structure with respect to the HCla ion. Hadzi and his co-workers (97a) have used deuteron resonance to study the structure of KDZg, where HX = trifluoroacetic acid (see Sect. VII D and XX G). The coupling constant and asymmetry para-... 

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