Oxygen-17 Quadrupole Coupling Parameters for Water in Its Various Phases

Abstract

Analysis of ¹⁷O NMR data in D₂¹⁷O ice yields a quadrupole coupling constant, $e^2\text{qQ\hspace{0.17em}/\hspace{0.17em}h\hspace{0.17em}=\hspace{0.17em}6.66\hspace{0.17em}±\hspace{0.17em}0.10}\mathrm{MHz}$ , and an asymmetry parameter, $\text{η\hspace{0.17em}=\hspace{0.17em}0.935\hspace{0.17em}±\hspace{0.17em}0.01}$ . Comparison with the data for liquid and gas indicates a temperature dependence of the ¹⁷O quadrupole coupling constant in the liquid and explains the unusual linewidth behavior for liquid D₂¹⁷O. Charge distributions in the water molecule in both the solid and gaseous states have been obtained by a valence‐shell atomic‐orbital population analysis based on the experimental data for the ¹⁷O quadrupole coupling parameters and the molecular dipole moment. The results were used to calculate the quadrupole coupling constant for the deuterium nucleus. Good agreement with experimental data was obtained for both the solid and gaseous states. Comparison of the calculations for the two phases suggests that the intermolecular effects in ice are mostly electrostatic.