Pressure effects on conformational equilibria. Difference in volume between conformers of 1,1,2‐trichloroethane

The effect of pressure on the equilibrium between conformers of 1,1,2‐trichlorocyclohexane has been studied using infrared spectra obtained with the diamond anvil cell. Changes in relative intensities of infrared bands show that the population of the more polar conformer (Cs symmetry) increases relative to that of the less polar conformer (C1 symmetry) with increasing pressure. Volume differences for converting the less polar to the more polar conformer are −3.8 cm3/mol in pure liquid and −1.8 cm3/mol in CS2 solution. These results are in agreement with values calculated by K. R. Crook and E. Wyn‐Jones [J. Chem. Phys. 50, 3445 (1969)].