60053-18-1Relevant academic research and scientific papers
Orientation in the Addition of HD Molecules to Buta-1,3-diene over ZnO Catalyst. A Method of Judging Heterolytic and Homolytic Dissociation of Hydrogen in Catalysis
Tanaka, Ken-ichi,Aomura, Kazuo,Okuhara, Toshio,Miyahara, Koshiro
, p. 1697 - 1706 (1981)
Selective 1,2-addition of HD molecules to butadiene on ZnO catalyst yielded 75percent of but-1-ene and 25percent of but-1-ene.Although the adsorption of HD on ZnO prefers conformation at room temperature and the reverse conformation at -40 deg C, reaction of HD at these two temperatures gave an identical ratio of / = 3.The dissociation of HD is in general expressed by In the case of homolytic dissociation H(I) and H(II) or D(I) and D(II) should be identical, i.e. β = 1, but in heterolytic dissociation it may not be unity.Provided that the hydrogen molecular identity is maintained in the hydrogenated products, the following equations were derived for n- and sec-butenyl intermediates: / = (1+ΑΒ)/(Α+Β) for sec-butenyl and / = (Α+Β)/(1+ΑΒ) for n-butenyl, where Α is a relative rate constant of the reaction of H(I) and H(II) or D(I) and D(II) with butadiene.Accordingly, in homolytic dissociation the simple relations / = / or / should be established for homolytic dissociation, because α = 1 and Β = 1, whereas / will be equal to neither / nor / in heterolytic dissociation.It was confirmed that the hydrogenation on MoS2 is brought about by homolytic dissociation but that on ZnO it is caused by heterolytic dissociation.A plausible mechanism assuming ?-allyl anionic intermediates. was proposed and it is explainable in terms of first-order kinetics in hydrogen pressure and the temperature-independent orientation in the 1,2-addition of HD.
