Ethylene Dimerization/Polymerization Catalyzed by (Adamantylimido)vanadium(V) Complexes Containing (2-Anilidomethyl)pyridine Ligands: Factors Affecting the Ethylene Reactivity

Abstract

V­(N-1-adamantyl)­Cl₂[2-(2,6-Me₂C₆H₃)­NCH₂(C₅H₄N)] showed both remarkable activity and selectivity (from 92 through >99.5% selectivity) in ethylene dimerization in the presence of MAO or MMAO, and the activity increased linearly upon increasing the ethylene pressure. The same reaction in the presence of Et₂AlCl or Me₂AlCl afforded ultrahigh molecular weight polyethylene. Both the ESR spectra and the ⁵¹V NMR spectra suggest that the chelate anionic donor ligand plays an important role in stabilization of the oxidation state in the catalyst solution even containing Al alkyls