TEMPERATURE-DEPENDENCE OF THE GAS AND LIQUID-PHASE ULTRAVIOLET-ABSORPTION CROSS-SECTIONS OF HCPC-123 (CF3CHCL2) AND HCFC-142B (CH3CF2CL)

The absorption cross sections for HCFC-123 (CF3CHCl2) and HCFC-142b (C H3CF2Cl) have been measured in the gas and liquid phases over the temp erature range of about 220-330 K. The liquid phase results were conver ted into effective gas phase cross sections using a wavelength shift p rocedure, thereby extending the gas phase cross sections to longer wav elengths. The results are compared with other available data and lend increased confidence in atmospheric lifetime calculations for these im portant industrial alternatives to the fully halogenated chlorofluoroc arbons.