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
作者:Ken-ichi Tanaka、Kazuo Aomura、Toshio Okuhara、Koshiro Miyahara
DOI:10.1039/f19817701697
日期:——
1,2-addition of HD molecules to butadiene on ZnO catalyst yielded 75% of [3-2H1]but-l-ene and 25% of [4-2H1]but-1-ene. Although the adsorption of HD on ZnO prefers [graphic omitted] conformation at room temperature and the reverse conformation [graphic omitted] at –40 °C, reaction of HD at these two temperatures gave an identical ratio of [3-2H1]/[4-2H1]= 3. The dissociation of HD is in general expressed
HD分子在ZnO催化剂上向丁二烯的选择性1,2-加成反应产生了75%的[3- 2 H 1 ] but-1-烯和25%的[4- 2 H 1 ] but-1-烯。尽管HD在ZnO上的吸附在室温下倾向于[图示省略]构象,而在–40°C时则相反[在图中图示]构象,但是HD在这两个温度下的反应给出的比率为[3- 2 H 1 ] / [4- 2 H 1 ] =3。HD的离解通常用[图解省略]表示。在均相离解的情况下,H(I)和H(II)或D(I)和D(II)应该是完全相同的,即β = 1,但在杂化解离中可能不是统一的。只要在氢化产物中保持氢分子的同一性,就可导出正丁烯基和仲丁烯基中间体的以下方程式:[3- 2 H 1 ] / [4- 2 H 1 ] = [ 2 H 0 ](1 + αβ)/ [ 2 H 2 ](α + β)对于仲丁烯基和[3- 2 H 1 ] / [4- 2 H 1 ] = [ 2 H