Ethylene interaction with deuterium

The interaction of an alkyne or alkadiene with deuterium leads to the formation of deuteroalkenes whose isotopic composition yields valuable information regarding possible reaction mechanisms. In an attempt to interpret in detail the deuteroalkene distributions, two approaches have been used. The first, due to Bond [163], is a simplified version of the general theory proposed by Kemball for the hydrogenation of ethylene (see Sect. 3.4) and has been used to interpret the results of the reaction of acetylene with deuterium [163—165]. The method comprises a steady state analysis of the reaction scheme... 

The catalytic interaction of acetylene with deuterium over a supported nickel catalyst has been found to yield ethylene-d2 as about 70% of the total ethylenes. Infrared analysis of the ethylene-da shows that at 80° the ratio of cis frans asymmetric is about 65 30 5 this analysis is, however, only semiquantitative, owing to the overlapping of bands. Lowering the temperature increases the proportion of ds and decreases the trans, the asymmetric being httle affected. 

Fig. lO.a The inset shows the postulated variation of the solubility parameter 8 caused by deuterium labeling (symbols and V correspond to labeled and nonlabeled copolymers, respectively) and due to the change in ethyl ethylene fraction x. The cumulative analysis, described in text, yields the absolute 8 value for deuterated dx (A) and protonated hx (V) copolymers as a function of x at a reference temperature Tref=100 °C determined interaction parameters (as in Fig. 9) allow us to determine two sets of differences AS adjusted here to fit independent PVT data [140,141] measured at 83 °C ( ) and at 121 °C (O). b The interaction parameter, yE/EE, arising from the microstructural difference contribution to the overall effective interaction parameter (hxj/dxpej) in Eq. (19) as a function of the average blend composition (xi+Xj)/2 at a reference temperature of 100 °C.%E/ee values are calculated (see text) from coexistence data ( points correspond to [91,143] and O symbols to [136]) for blend pairs, structurally identical but with swapped labeled component. X marks %e/ee yielded directly [134] for a blend with both components protonated. Solid line is the best fit to data... 

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