TEMPERATURE-DEPENDENCE OF ELECTRIC FIELD-GRADIENT INDUCED BIREFRINGENCE IN CARBON-DIOXIDE AND CARBON-DISULFIDE

Equipment for measurements of the electric field-gradient induced bire fringences of gases and vapours is described, and results for CO2 and CS2 over ranges of temperature (approximate to 290-440 K) and pressure (up to 616 kPa) are reported. Analyses of the data show that at 300 K the temperature-independent contributions to the effects are small bu t not negligible (CO2, 2.4 +/- 1.2%; CS2, - 5.4 +/- 3.5%) and definiti ve molecular quadrupole moments are obtained [CO2, Theta = (-14.3 +/- 0.6) x 10(-40) C m(2); CS2, Theta = (11.5 +/- 0.5) x 10(-40) C m(2)]. In the case of CO2, the results confirm the correctness of Buckingham and Disch's original single-temperature investigation of this species. (C) 1997 Elsevier Science B.V.