离子液体体系中1－丁烯二聚反应的研究

 研究了在强酸性AlCl3／Et2AlCl／［BMIM］Cl型离子液体体系中过渡金属化合物对1－丁烯二聚反应的催化作用．结果表明，［BMIM］Cl对强酸性AlCl3／Et2AlCl催化剂催化1－丁烯高聚反应有明显的阻聚作用，并显著提高了1－丁烯二聚的选择性．在过渡金属化合物中，含镍化合物对1－丁烯二聚反应有最好的催化效果．在最佳反应条件下，1－丁烯的转化率可达95．1％，二聚产物C8烯的选择性为85．8％．同时，对1－丁烯二聚反应的机理进行了初步探讨．

Studies on Dimerization of 1-Butene in Ionic Liquid System

The dimerization of 1 butene has attracted much attention because C 8 olefins are widely used in chemical industry, such as in the manufacture of linear low density polyethylene comonomers, special detergents, synthetic lubricating oils, etc . The dimerization of 1 butene catalyzed by transition metal (such as nickel, zirconium and cobalt) compounds was systematically investigated using 1 butyl 3 methyl imidazolium chloride ionic liquid as solvent. The results showed that the conversion of 1 butene and the selectivity for C 8 olefins could be enhanced by adjusting the composition of the catalyst. Among the transition metal compounds investigated, the nickelous chloride exhibited the best catalytic performance for 1 butene dimerization, the conversion of 1 butene was up to 95 6% and the selectivity for C 8 olefins was 85 8%. Zirconium chloride was active for the dimerization reaction, while the selectivity for C 8 olefins was low. The catalytic activity of cobalt compounds was low. The other transition metal compounds tested in this work could not catalyze 1 butene dimerization in ionic liquid. Accordingly, 1 butene could be dimerized effectively in ionic liquid under mild conditions no need of organic solvent and strict oxygen free and water free conditions, the good solubility of nickel compounds and the poor solubility of olefins in polar and non coordinating ionic liquid make it possible to separate the products from solvent by decantation. The possible reaction mechanism was also discussed.