Reaction between Deuterium and Hexenes

As will be seen, selectivity for formation of hexane-d2 from 1-hexene rises steadily with increasing temperature of activation and seems to increase a little with an increase in temperature of activation beyond that at which crystallinity first appears. For example, in a run on catalyst activated at 421°, D2 was 94% at an alkane yield of 21%. Amorphous catalysts were not examined at higher temperatures of activation than those listed. 

Although selectivity for hexane-dg is also high in the reaction between deuterium and raws-2-hexene on both amorphous and crystalline catalysts activated at 400° (runs 258 and 276 of Table VII), it is somewhat lower than with 1-hexene. 

In view of the isomerization of hexenes which accompanies the addition of deuterium, one might expect that not all hexane-dg derived from 1-hexene would be hexane-l,2-d2 nor all that derived from 2-hexene, hexane-2,3-d2. We examined the CgHj+j and 41 fragment peaks to get some information about this. The runs with iran5-2-hexene are particularly unambiguous. 

That is, the deuterium content of CjII/j was drastically less than that of CeHi+4. This corresponds to the appearance of deuterium on 44% of C-1 assuming no multiple exchange on C-1 and no exchange on C-6. The corresponding figure for run 257 is 73%. Correction for the isotope effect would increase these values by a few percent. Runs 275 and 257 were on amorphous and microcrystalline catalysts, respectively, both activated at 400°, both carried to 100% hydrogenation by relatively 

In analyzing the results for runs with I-hexene there were some inconsistencies in analysis on the CgHi+j and 04 peaks. These gave some evidence for formation of hexane-2,2- 2 as well as hexane-2,3-d2  

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