Isomerization high vacuum technique

The isomerization of butanes using a high vacuum technique for the purification and introduction of the reactants was investigated (Leighton and Heldman, 5). It was found that completely anhydrous aluminum bromide did not act as a catalyst for the isomerization at 85° the addition, however, of a small amount of hydrogen bromide to the reactants caused n-butane to isomerize. 

In order to test the validity of the postulated mechanism of isomerization, deuterium bromide-aluminum bromide instead of hydrogen bromide-aluminum bromide was used as an isomerization catalyst (Pines and Wackher, 23). The reactions were carried out under controlled conditions using a high-vacuum technique. The experimental conditions are summarized in Table XIV. 

In order to obtain some conclusive data as to the course of isomerization, several experiments were made using highly purified reagents and a high vacuum technique (Mavity et al., 32). 

Isomerization of n-Pentane Using High Vacuum Technique... 

I d like to comment on the experimental methodology used to study the reaction. Herman Bloch points out that Pines always was careful and used the best available techniques to do his work. The use of high vacuum technique here illustrates this point. The isomerization of cycloalkanes was fully studied by several students collaborating with Pines (8-17). Again they used high vacuum technique. And toward the end of this research carbon 14 labeling was done. Again, this illustrated Bloch s point use of the best techniques. 

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