TEMPERATURE AND PRESSURE-DEPENDENCE OF THE ELECTROOPTICAL KERR EFFECT OF SULFUR-DIOXIDE

Measurements of the electrooptical Kerr effect of sulfur dioxide over a range of temperature (≈299-490 K) and pressure (≈45-200 kPa) are reported. Analysis of the temperature dependence of the first Kerr virial coefficient in conjunction with the known mean polarizability and Rayleigh depolarization ratio yields high-precision values of the optical-frequency polarizabilities of the molecule. Results (1040αxx/C m2 V-1, etc., x direction perpendicular to molecular plane, y and z directions in plane, z coincident with C2 axis) emerge as 3.30 ± 0.04, 5.80 ± 0.06, and 3.88 ± 0.06 at 632.8 nm. The first and second Kerr hyperpolarizabilities make only very small contributions to the Kerr constant so that rather imprecise, but nevertheless valuable, estimates of these two properties are obtained. The pressure dependence of the effect is considered in relation to a statistical-mechanical theory that identifies the collision-induced polarizability as the dominant contributor to the second Kerr virial coefficient of a dipolar gas. © 1990 American Chemical Society.