1-Hexene, exchange with deuterium

The reaction of 1-hexene with deuterium over nickel-silica at 105° yields hexanes distributed as shown in Table VI (49) no observations on isomerization or exchange were made. The hexanes become progressively more deuterated as the D /hexene ratio is raised. Isomerization of n-hexenes has been observed during their hydrogenation over Raney nickel (50). 

Isotopic distributions of toluene exchanged at 110° in runs with a deuterium/toluene ratio of 5.5 appear in Table XI. Detectable activity appeared after activation at 215°, was a maximum at about 330°, and then declined. Most runs on toluene were preceded by a run with 1-hexene and deuterium at 64°. Information on the hexene runs is contained in Fig. 10 and Tables IV, V, VII, and IX. The toluene run, 250, was followed by a run with hexene and runs 240, 247, and 10 were not connected with hexene runs. 

Process (5), Isotopic Exchange of Reactant Hexene. However, the moles of hydrogen atoms from the positions equilibrated in 2-hexene is 0.108(0.65) =0.070. This is much too small a quantity to mix with 0.20 moles of deuterium atoms to give (D ) = 0.35 even if we allow for the extra hydrogen added to the pool in the isomerization of cis- to trans-2-hexene. The only other source of hydrogen is in exchanged 1-hexene. This provides approximately the needed ratio D/H, for (D ) = 0.35. On this picture, 1-hexene in run 233 results from equilibration with a pool... 

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