ON THE INTERNAL FIELD CORRECTION IN FAR-INFRARED ABSORPTION OF HIGHLYPOLAR-MOLECULES IN NEAT LIQUIDS AND DILUTE-SOLUTIONS

Far-infrared absorption spectra for liquid acetone, methylene chloride , acetonitrile, methyl iodide, and their dilute solutions in cyclohexa ne at 20-degrees-C are measured by molecular laser spectrometer. Measu rements of dielectric loss of polar liquids and solutions in the frequ ency range 2-300 GHz are made using a number of different techniques. These two sets of measurements are combined with those made using a Fo urier transform spectrometer in order to cover the frequency range up to 250 cm-1 and total integrated absorption intensities are calculated . It is shown that the discrepancy between experimental integrated abs orption and the theoretical results given by Gordon's sum rule with th e Polo-Wilson internal field factor can be explained in the context of Bossis' theory. This theory gives a better agreement with the experim ental integrated absorption intensity for these liquids.