Determination of the (Na+) Sternheimer antishielding factor by 23Na NMR spectroscopy on sodium oxide chloride, Na3OCl

The (Na+) Sternheimer antishielding factor gamma(infinity) (Na+) was determined by Na-23 NMR spectroscopy on sodium oxide chloride, Na3OCl. The quadrupolar coupling constant of the sodium ion in Na3OCl was determined to QCC = 11.34 MHz, which presents the largest coupling constant of a sodium nucleus observed so far. Applying a simple point charge model, the largest principal value of the electric field gradient at the sodium site was calculated to V-zz = - 6.76762 . 10(20) V/m(2). From these values we calculated the (Na+) Sternheimer antishielding factor to gamma(infinity) (Na+) = - 5.36. In sodium oxide, Na2O, we observed an isotropic chemical shift of delta(CS) = 55.1 ppm, referenced to 1 M aqueous NaCl (delta = 0 ppm). (C) 2000 Elsevier Science B.V. All rights reserved.