Study On Properties Of Catalytic Systems For Ethylene Tetramerization

Linear lowα-olefins are important comonomers to produce copolymer and many fine chemicals. Ethylene oligomerization is the best method of synthesizing linear lowα-olefins. One of the biggest obstacles that prevent the development of the technic is the problem of catalyst. 1-Octylene is the important chemical product and intermediate with the superior mechanism performance and optics property. So it is very important to study the catalysts of ethylene tetramerization.According to the mechanisms of ethylene tetramerization, we have studied three PNP ligands and seven donors in PNP/Cr(Ⅲ)/cocatalyst catalytic systems. The studies focus on the 1-octene selectivity and catalyst activity. And determine the better structure of ligand is methyl in m-benzene.We divide the seven donors to three kinds. The 1-octene formation selectivity and catalyst activity of dichloromethane are priory to trichloromethane and tetrachloromethane. The catalyst activity of 1,1,2-trichloroethane is better than 1,1,1-trichloroethane, and the 1-octene formation selectivity is also better. The 1-octene formation selectivity and catalyst activity of 1-chlorobutane are better than 1-bromobutane.