S u m m a r y The rate and orientation of addition of hepta-olefins the substituent has virtually no effect on the rate of fluoropropyl radicals to a series of fluoro-olefins in the addition. Only with 1, l-difluoroethylene and 3,3,3-trigas phase has been determined by a competitive method. fluoropropene does there appear to be appreciable retarda-

subsequent chain carrying processes involve hydrogen abstraction as much as bromine abstraction :The almost equal importance of hydrogen and bromine abstraction from bromodichloromethane leads to a mixture of products in which both dichloromethyl (CHCI,*) and bromodichloromethyl (CBrCI,.) radicals are chain carrying species. In contrast to earlier reports of liquid phase studies the radical which predominates in addition to alkenes in the gas phase is the bromodichloromethyl radical.

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