Temperature dependence of intensities of the 8–12 μm bands of CFCl3

The absolute intensities of the 8–12 μm bands from freon 11 (CFCl₃) were measured at temperatures of 294 and 216°K. Intensities of the bands centered at 798, 847, 934, and 1082 cm^-1 are all observed to depend on temperature. The temperature dependence for the 847 and 1082 cm^-1 fundamental regions is attributed to underlying hot bands; for the ν₂ + ν₅ combination band (934 cm^-1), the observed temperature dependence is in close agreement with theoretical prediction. The implication of these results on atmospheric i.r. remote-sensing is briefly discussed.