Temperature dependence of the infrared absorption cross sections of carbon tetrachloride

Infrared absorption cross sections for carbon tetrachloride are reported over the range 730 to 825 cm⁻¹ at four different temperatures (298, 273, 248, and 223 K). The absorption cross sections were measured using Fourier transform spectroscopy at a spectral resolution of 0.05 cm⁻¹. The integrated band intensity for this spectral region was found to be (5.75±0.30) × 10⁻¹⁷ cm² molecule⁻¹ cm⁻¹, independent of temperature. The absorption cross sections were found to be essentially independent of spectral resolution (between 0.05 and 0.25 cm⁻¹) and foreign gas pressure (0–1 atm at 298 K, 0–200 torr at 223 K), although changes of about 5 to 10 % were noted in the structured regions of the spectrum. Our measured band intensity appears to be about 15 % higher than recently published data. These differences are discussed in terms of their effect on previously reported stratospheric CCl₄ altitude profiles.