Novel fluorinated monomers bearing reactive side groups Part 1. Preparation and use of ClCF2CFC1I as the telogen

The addition of IC1 to chlorotrifluoroethylene leading to a ClCF2CFClI (I)/Cl2CFCF2I (II) mixture is described. Four different ways of initiation (thermal, photochemical, or the presence of redox catalysts or radical initiators) were used in order to get optimized yields and amounts of isomer I. Thermal initiation led to quantitative yields whereas the photochemically induced reaction usually produced the highest proportion of isomer I. Excellent yields of isomer I were obtained at 140 °C. The batch process was more interesting in both selectivity and yield. The activation energy of the reaction was 27 kJ mol−1 and elucidation of the mechanism was proposed in terms of a radical process.