Reaction between Olefins and Deuterium

A complicated array of processes occurs between olefins and deuterium upon chromia activated at lower temperatures. These are listed at the beginning of Section VIII. Although it appears impossible to present a detailed mechanistic interpretation of this array with any 

For reasons given in Section VIII, the various processes are probably associated in the following fashion. The numbers refer to the list at the beginning of Section VIII. 

Sets A, B, and C must occur on different sites. For amorphous catalysts activated at temperatures below 360° or so, D could be associated with the sites of set A if (4 ) is low at these sites. This could also be true for amorphous catalysts activated at 400° and for microcrystalline a-Cr203 but, owing to the different ratios of isomerization to hydrogenation, there would have to be some difference between the sites for set A on these catalysts and those activated at lower temperatures. 

On amorphous catalysts, activity for the exchange of methyl in toluene goes through a maximum with increasing activation temperature 

The exchange of the ring in benzene and toluene depends upon the temperature of activation in a way differing from the processes of sets A, B, C, and D (Section VIII,F). 

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