EFFECTS OF HIGH PRESSURE ON THE NEAR ULTRAVIOLET VAPOR ABSORPTION SPECTRUM OF BENZENE IN VARIOUS DILUENT $GASES^{*}$

Abstract

“The near ultraviolet vapor absorption spectrum of benzene has been recorded in various diluent gases covering a density range that extends from the vapor density of benzene through the density region of liquid hydrocarbons. The wavelength of absorption shifts to the red smoothly with an increasing slope with increasing density of diluent gas, but is linear with dielectric constant. The frequency of absorption then decreases with increasing dielectric constant and has an increasing slope. The smoothness of the curves suggests that there is no essential difference in mechanism between that described by the collision theory generally used to interpret wavelength shifts resulting from intermolecular interactions at low densities and the mechanism described by the statistical theory that would be applied in the region of liquid densities. Data is presented on carbon dioxide as a diluent, both above and below the critical temperature. Behavior in liquid and gaseous phases at equal densities is presented.”