Vanadium procatalysts bearing chelating aryloxides: structure–activity trends in ethylene polymerisation

High-valent vanadium complexes bearing a variety of chelating aryloxides including di- and linear tri-phenolates, C/N-capped tripods, phenoxyimines and calixarenes type ligands, when used in combination with dialkylaluminium halides as co-catalyst and a reactivator, are found to act as highly active catalytic systems for a-olefin polymerisation. Pro-catalyst structure–catalytic activity trends can be identified for the various ligand families employed.