Reaction kinetics of the ethene tetramerization catalyst system CrCl3(THF)3, Ph2PN(iPr)PPh2 and MAO: The unexpected and unusual formation of odd-numbered 1-olefins

This paper describes a kinetic investigation of the ethene tetramerization catalyst system comprising CrCl3(THF)(3), a bis(diphenylphosphino)isopropylamine Ph2PN(Pr-i)PPh2 as ligand and MAO as catalyst activator. The main focus of the experimental study lied on the influence of the ligand to chromium molar ratio on the catalyst performance and the selectivity towards 1-octene. It was found that a sub-stoichiometric ligand/Cr ratio leads to a Schulz-Flory product distribution, while unusual odd-numbered 1-olefins as by-products were formed. (C) 2008 Elsevier B.V. All rights reserved.