Two Chemical Determinations of the Population of Conformations in 1,3-Butadiene

On the role of s-cis conformers in the reaction of dienes with OH radicals

“…They are reported in Table 2 together with several results from experimental work. 2,3,[13][14][15][16] At the PMP2 and BHandHLYP levels the s-cis conformer is twisted by 38.9 and 35.9 , respectively. We have studied the channels for OH addition to s-cis-isoprene and s-cis-and s-trans-butadiene involving addition at four distinct positions.…”

Synthesis and microbial toxicity of dinitrobutadienes and related compounds

“…The report (Vasileva et al, 1961) Erysiphe polygoni Up = Uromyces phaseoli moment of 0.71 D. is not consistent with structure 1 but is explicable by an equilibrium between 1 and c. Such an equilibrium, about 4% in the "S-cis" form (Smith and Massingell, 1961) has been observed with 1,3-butadiene (Bine, 1956), but the dipole moment of 1,3-butadiene is indistinguishable from zero (Bannay and Smyth, 1943;Wienges et al, 1966). In the case of c the dipole moment would be significantly greater than in the "S-cis" form of butadiene.…”

Study on the Selective Hydrogenation of Butadiene in C₄-Hydrocarbon Fraction (Part 3)

“…These values of t/c ratio were similar to those previously reported2),5) which were measured in the initial stage of the reaction when isomerization did not yet occur. Therefore, it was assumed that the transoid and cissoid type of butadiene6), 7) were not interconverted at the transition state on the catalyst surface and the similar ratio of trans-and cis-2-butene to that of transoid and cissoid butadiene was resulted. However, after disappearance of butadiene at higher temperature (>110°C), t/c ratios of formed 2-butenes were low.…”