Counterion effects on the 183W NMR spectra of the lacunary Keggin polyoxotungstate [PW11O39]7–. Relativistic DFT calculations

The 183W NMR spectra of the lacunary Keggin polyoxotungstate [PW11O39]7– feature noticeable differences according to the counterion (Li or Na). Such differences are modeled by ion pairs where the lacuna is occupied by a Li(H2O)+ or Na(H2O)+ group through relativistic DFT calculation of the tungsten chemical shifts.