Selective ethylene trimerization with a cyclopentadienyl-arene titanatrane catalyst

Abstract

Cyclopentadienyl-arene titanatrane catalysts activated by methylaluminoxane (MAO) cocatalysts were studied for the trimerization of ethylene. The introduction of electron-rich multidentate ligands to the catalysts' active sites resulted in good productivity and selectivity for ethylene trimerization. Various amounts of MAO were tested, and methods of its introduction to the system were varied. It has been shown that pre-alkylation of the catalyst with MAO increases the productivity of ethylene trimerization. The effects of reaction temperature and pressure on 1-hexene productivity and selectivity were also studied. The rate of ethylene conversion was approximately first order with respect to ethylene concentration. 1-Hexene was produced under moderate conditions, allowing energy savings to be gained through lower temperature reactions.