Pressure dependence of¹H and¹⁹F chemical shifts in 1,1-difluoroethylene gas and in gaseous mixtures

Abstract

We have measured the chemical shifts, 8, and 'second virial shielding coefficient ', al, for gaseous 1,1-difluoroethylene and its mixture with other gases at varying pressures (~ 10-45 atmospheres). The 8 vs p (density) plot for 1H and 19F resonances is found to be linear within the pressure range studied. The sign of ~1 is negative. The influence of perturbers on 8 and a 1 is in the following order : Xe > SF~ > Kr> SiFa > CH4 > CF4 (spherical top molecules) and C~H6 > C2H4 > HC1 > CO2 (non-spherical top molecules). These trends are true for polar and non-polar solutes.