Effects of High Pressure on the Near Ultraviolet Vapor Absorption Spectrum of Benzene in a Number of Diluent Gases

Abstract

The absorption spectrum of benzene vapor in a number of gaseous diluents over a wide range of diluent densities has been obtained. The wavelength of absorption shifts to the red in the gases A, H₂, N₂, CO₂, O₂, CO, C₂H₆, and C₂H₄, to the blue in the diluents He and Ne. Since the light absorber is the same in each case, the relative rates of shift with density should be a function of the physical properties of the diluents. However, no simple correlation has been found to exist between relative shift and such properties of the solvents as polarizability or dielectric constant. Dispersion theory predicts only roughly the relative shifts. No satisfactory explanation has been found for the blue shift obtained in He and Ne.