29/28, 30/28Silicon, 34/32sulfur and 80/77selenium isotope-induced fluorine chemical shifts through two bonds.

Isotope effects on fluorine chemical shifts induced by heteroatoms bonded covalently to a carbon atom bearing fluorine atoms were studied. For each compound, the isotope-induced chemical shifts 2delta19F(X) through two bonds were measured for the heteroatom (X = 29/28Si, 30/28Si, 34/32S and 80/77Se). The 1delta19F(13/12C) values for the carbon bonded to the fluorine atoms were also recorded.