Polarization of electronic transitions in aromatic hydorcarbon molecules and their mono- and di-valent ions

Abstract

On irradiation of glassy solutions of aromatic hydrocarbon mono- and di-negative ions with ultra-violet light photo electron ejection occurs according to the reactions: When one uses plane polarized light of a wavelength corresponding to an absorption band of the ion originally present, the solutions become permanently dichroitic. The differences in extinction of these dichroitic solutions for plane polarized light with its electric vector perpendicular and parallel to that of the primary light were plotted against the wave number of the absorbed light. From these diagrams the relative directions of polarization of the electronic transitions of some alternant aromatic hydrocarbon molecules and negative ions were determined. The absolute directions could be found by comparing the results obtained for the molecules with those of polarization measurements on the crystalline hydrocarbons reported in the literature.