Temperature dependence of electric field-gradient induced birefringence in carbon dioxide and carbon disulfide

Equipment for measurements of the electric field-gradient induced birefringences of gases and vapour is described, and results for CO2 and CS2 over ranges of temperature (≈ 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 but not negligible (CO2, 2.4 ± 1.2%; CS2, −5.4 ± 3.5%) and definitive molecular quadrupole moments are obtained [(CO2, Θ = (−14.3 ± 0.6) × 10−40 C m2; CS2, Θ = (11.5 ± 0.5) × 10−40 C m2]. In the case of CO2, the results confirm the correctness of Buckingham and Dischʹs original single-temperature investigation of this species.