Donor–Acceptor Metallocene Catalysts for the Production of UHMW‐PE: Pushing the Selectivity for Chain Growth to Its Limits

Plastic fantastic! Donor–acceptor zirconocenes with a donor (P)-substituted fluorenyl ligand and an acceptor (B)-substituted cyclopentadienyl ligand (see structure) are highly active ethylene polymerization catalysts that reveal an ultrahigh selectivity for chain propagation even at high temperatures, giving access to ultrahigh-molecular-weight polyethylenes (viscosity-average molecular weights Mη>1×106 g mol−1).