Tailoring the metallocene structure to obtain LLDPE by ethene homopolymerization: An experimental and theoretical study

The mechanism of formation of branched polyethylene in the polymerization promoted by mesometallocene/MAO systems has been investigated by combining DFT calculations and experimental results on differently featured meso-zirconocenes. A possible explanation for the required meso structure in the formation of branches considers a competition of ethene insertion and β-hydrogen transfer to the monomer. General mechanistic considerations in order to design catalytic systems able to synthesize LLDPE by ethene homopolymerization have been outlined. © 2008 American Chemical Society.