Molecular polarisability: the molar Kerr constants of allyl halides as solutes in carbon tetrachloride

Abstract

As solutes in carbon tetrachloride at 25°, allyl chloride, bromide, and iodide have molar Kerr constants (× 10¹²) of 48·2, 96·6, and 99·1, and dipole moments (D) of 1·75, 1·73, and 1·56, respectively. When the anisotropic carbon–halogen bond polarisabilities previously found applicable to ethyl and isopropyl halides are used, the new measurements are reconcilable with the non-planar conformations specified by Bowen, Gilchrist, and Sutton, but not with mixtures of s-cis- and s-trans-conformers alone. Attempts to predict average molar Kerr constants, by assuming hindered internal rotations to be due to van der Waals and dipole-induced dipole interactions, are also described.