Reactions of CH4 with the Halogens

Although there is still considerable controversy about the relative importance of the different possible modes of pyrolysis of saturated hydrocarbons under inhibiting conditions, it is generally agreed that the uninhibited reactions proceed principally by a radical chain mechanism. 

The first general mechanism to account for the presumed first-order kinetics of these and other organic pyrolysis reactions was proposed by 

This may in part arise from an overestimation of the standard entropy of CHs by 1 to 2 cal/mole- K (Table XIII.5). 

Of course for CH4 4 I2 the equilibrium is in favor of starting materials, and in fact HI reacts with CH3I to produce them. In the case of CH4 -f Br2, the equilibrium is not too far over toward CHsBr - - HBr (Table XIII.5). 

Rice and Herzfeld. Subsequent work has strengthened their basic premises, which may be summarized as follows  

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