title: Homogeneous vanadium-based catalysts for the Ziegler-Natta polymerization of alpha-olefins.
abstract: Although their activity is often inferior to that of other systems, the use of vanadium-based catalysts in homogeneous Ziegler-Natta polymerizations allows the preparation of high-molecular-weight polymers with narrow molecular-weight distributions, ethene/alpha-olefin copolymers with high alpha-olefin incorporation, and syndiotactic polypropene. The main reason for the low activity of these catalysts is their deactivation during catalysis by reduction of active vanadium species to low-valent, less active or inactive species. We here present an up-to-date review of this area with particular emphasis on the attempts to improve catalyst performance and stability by the use of additives or ancillary ligands.
authors.affiliation: Debye Institute, Department of Metal-Mediated Synthesis, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands.
authors.forename: Henk
authors.initials: H
authors.lastname: Hagen
authors.forename: Jaap
authors.initials: J
authors.lastname: Boersma
authors.forename: Gerard
authors.initials: G
authors.lastname: van Koten