The results of the lighthyphen;scattering study are presented. Measurements made in the absence of an applied electric field gave size parameters and a molecular weight for this rodlike molecule which are in good agreement with results obtained by other workers. These are a molecular weight of 49.5times;106and a radius of gyration of 940(plusmn;28) Aring; corresponding to a length of 3200 Aring; and a diameter of about 150 Aring;. The sample was very monodisperse. The second osmotic virial coefficient was zero. The application of alternating electric fields to solutions of polar or electrically anisotropic molecules results in changes of the angular distribution of the intensity of the scattered light and the introduction of an alternating scattered intensity component of twice the frequency of the applied field. The way in which these effects can be used to determine the electrical characteristics of the molecules is described. The solutions were subjected to fields up to about 500 V cmminus;1at frequencies up to 30 kc/sec, and it was found that the molecules possessed both a permanent dipole moment mgr; and electrical anisotropy bgr;. The values obtained were mgr;=4.1times;104D and bgr;=4.3times;104D and these are in agreement with previously reported values. Consideration of the frequency dependence of the intensity changes enabled a value for the rotary diffusion constant to be estimated.
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