KrF laser induced telomerization of bromides with olefins. Part 2. BrC2F4Br and BrC2F4C2H4Br with C2H4 and C2F4

Article abstract of DOI:10.1002/bbpc.19900940811

We investigated the photochemical insertion of one to three olefin units into a CBr bond of two dibromides in gas phase. Unexpected high quantum yields (up to 30) were found in the system BrC₂F₄Br + C₂H₄ for the product BrC₂F₄C₄H₈C₂F₄Br and some others. Therefore they cannot be radical combination products, but must arise from chain propagation. To explain their formation, accumulation of C₂F₄ must be assumed. The addition of ethylene to a radical can be reversed by Br atoms. This reaction strongly influences the product spectrum. Synthesis of BrC₂F₄C₄H₈C₂F₈Br would be economic by the laser method. The preparation of BrC₂H₄C₂F₄C₂H₄Br was also much improved over previous methods.