Addition of bromine atoms to double and triple bonds

4 ADDITION OF BROMINE ATOMS TO DOUBLE AND TRIPLE BONDS 

The present author, over several years, has published a number of papers on the relative reactivity of olefins towards addition of HBr, using competition methods, and has derived some mechanisms without obtaining absolute rates [65, 66]. The reaction is a complex one. The initial radical is in an excited state, and is deactivated most effectively by 

The absolute rate studies are summarized in Table 14 and relative rate studies are reported in Table 15. 

Relative reactivity of various alkenes towards bromine atoms [65] 

The relative rate study reveals a tremendous variation in the reactivity of the simple olefins, and indicates the highly electrophilic character of the bromine atom. It would be very interesting to obtain equivalent data for the other halogen atoms, or, better still, absolute rate data for the various olefins with the various halogen atoms through a fairly comprehensive list of olefins. It is this sort of kinetic information which is so important to a fundamental understanding of how molecules react, and it is those data that are all too frequently missing in kinetics. 

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