UV-ACTIVATED CHLORINATION

A method of producing alkanes containing chlorine by addition of chlorine to C-C double bonds or C-C triple bonds or by exchange of hydrogen for chlorine by contacting the starting compound in the gas or liquid phase with elemental chlorine and irradiating the reaction mixture with UV light having a wavelength of lambda>=280 nm. In this way pentachloroethane can be produced from trichloroethylene, CFC-113 from HCFC-123 or HFC-133a, CFC-112a from HCFC-142b, or HCFC-123 from HCFC-133a. The method also is suitable for separating photochlorinatable impurities from HFC-365-mfc to obtain purified HFC-365-mfc. Advantages include high yields and excellent selectivity.