A first-principles computational 17O NMR investigation of metal ion-oxygen interactions in carboxylate oxygens of alkali oxalates

17O NMR parameters, including chemical shift (CS) and electrical-field gradient (EFG) tensors, are calculated for oxalate compounds containing various different alkali ions using a DFT infinite periodic solid approach. This DFT study allows correlations to be found between the metal ion and oxygen interaction and the 17O NMR interaction parameters. The 17O CS shows greater sensitivity to the local alkali ions than that shown by the 13C CS in the same compounds. It is found that the combination of metal ion-oxygen bond strength and cation size induce a deshielding shift up to ∼70 ppm of 17O δiso. The results also show the effects of different M-O interactions and C-O bond characteristics on the orientation of 17O CS tensor components, and suggest that the 17O quadrupolar parameters are systematically sensitive to the local cation environments around the carboxylate oxygen.