On the relativistic effects on 19F nuclear magnetic resonance chemical shifts in the presence of iodine atoms

Abstract

In this paper, the influence of the relativistic effects on 19F NMR chemical shifts has been thoroughly investigated in diverse fluorine compounds containing one or more iodine atoms. It was found that the magnitude of the relativistic correction to fluorine shielding constant strongly depends on the arrangement of iodine atom(s) in molecule relative to the fluorine atom under consideration. Thus, specific cases were found where the relativistic corrections to fluorine shielding constants reached at as much as 6–8 ppm, causing noticeable changes in the corresponding fluorine chemical shifts. In general, the relativistic corrections to fluorine shielding constants were found to vary in the range of 0–3 % of their nonrelativistic values.