Deuteron Quadrupole Coupling Constants of the Methyl and Methylene Groups of Ethanol from the Direct 13C-2H and 2H-2H Couplings in 2H-NMR Spectra

Article abstract of DOI:10.1021/j150660a038

The deuteron quadrupole coupling constants, Q_D, of 13C(2)H3CH2OH and CH3(13)C2H2OH were measured in two different nematic solvents by employing the quadrupolar splitting and 13C-2H and 2H-2H dipolar splittings in 2H NMR spectra.In order to obtain the most accurate values for Q_D, vibrational averaging of the dipolar couplings and ab initio calculations of the C-D bond asymmetry correction were used in the theoretical treatment of the experimental data.The values found in ZLI-1167 are 186.6 and 178.2 kHz and in phase IV are 180.7 and 176.6 kHz for the methyl and methylene groups, respectively.Using the previously obtained 2H NMR relaxation data and the Q_D value determined in ZLI-1167, we calculated the internal rotation coefficient of the methyl group to be 0.68E11 s^-1.