Nuclear Magnetic Shielding in F2

The ¹⁹F chemical shift between gaseous F₂ and SiF₄ has been measured to be − 596.0 ± 0.2 ppm at 30°C. With a recently established absolute shielding scale for ¹⁹F this value yields an absolute shielding in F₂ of − 232.6 ppm. Combination of this with the measured spin–rotation constant leads to a separate determination of experimental values for ${\sigma }_F^d$ and ${\sigma }_F^p$ , with arbitrary choice of gauge origin, which are then compared with available theory. An estimate of the vibrational effects is given.