Dispersion of the Kerr Constant of the Acridine Orange-Polyglutamic Acid Complex

Abstract

The Kerr effect (linear electric birefringence) is generally measured in transparent regions of the spectrum and used to obtain information about the anisotropy of the polarizability. In the vicinity of an electronic absorption, the Kerr constant exhibits anomalous dispersion, and the form of this dispersion is related to the direction of the transition moment for the particular electronic transition. The origin of these effects is reviewed. Experimental work is presented on the dispersion of the Kerr constant for the acridine orange-polyglutamic acid complex in DMF. From the shape of the dispersion curve, the polarization of the absorption band for the free dye can be assigned. A structure of the dye-polymer complex compatible with these and other published data is that of a lefthanded helix bound to the polymer helix so that the long axis of the dye molecule is parallel to the long axis of the polymer helix. © 1967, American Chemical Society. All rights reserved.