The19F chemical shift between gaseous F2and SiF4has been measured to be minus;thinsp;596.0thinsp;plusmn;thinsp;0.2 ppm at 30deg;C. With a recently established absolute shielding scale for19F this value yields an absolute shielding in F2of minus;thinsp;232.6 ppm. Combination of this with the measured spinndash;rotation constant leads to a separate determination of experimental values forsgr;Fdandsgr;Fp, with arbitrary choice of gauge origin, which are then compared with available theory. An estimate of the vibrational effects is given.
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