Temperature dependence of Kerr coefficient of some homologous liquids

The electro optical Kerr coefficient of organic liquids belonging to the homologous series of Ketone, Aldehyde and Nitriles are measured over the temperature range of 285K to 313K. To within experimental errors, the results indicate that the Kerr constant can be expressed as a quadratic function of reciprocal temperature. The contributions due to the hyperpolarizabilities and the dipolar orientations have been evaluated from the least-square fits of the experimental data to the quadratic expression in the Kerr coefficient. A decreasing trend in the values of the contribution due to second order hyperpolarizabilities has been noticed with increasing chainlength by CH2 intervening groups in these series. This fact has been supported by observing a similar trend in the variations of the inductive effect arising from different substituents in the molecular structures of the liquids.