50 years ago, Karl Ziegler and Giulio Natta were awarded the Nobel Prize for their discovery of the catalytic polymerization of ethylene and propylene using titanium compounds and aluminum-alkyls as co-catalysts. Polyolefins have grown to become one of the biggest of all produced polymers. New metallocene/methylaluminoxane (MAO) catalysts open the possibility to synthesize polymers with highly ...

Zirconium and Hafnium Ziegler-Natta catalysts containing the [(2,6C12C6H3NCH2CH2)2NMe] ([ArciN2NMe]) ligand were prepared and employed in the polymerization of 1-hexene. Hafnium Ziegler-Natta catalysts containing the [(2,6X2C6H3NHCH2)2C(CH3)(2-C5H4N)] ([Arx2NPy]) (X = Cl or F) ligand were also prepared for use in 1-hexene polymerization studies. Compounds of the type [Ligand]MR 2 (R = Me, i-Bu)...

Syndiotactic 1,2-polybutadiene (sPBD) is an important industrial polymer with a wide variety of uses; however, there is only a very limited number of catalysts currently capable of producing this polymer with a high degree of syndiotacticity. Only one such catalyst has been structurally characterized, when in 1967 Natta et al. published a low-resolution crystal structure of the cobalt complex [...

The deconvolution of the molecular weight distribution (MWD) polyolefins into Schultz–Flory most probable distributions has become standard method to identify number site types on multiple-site-type olefin polymerization catalysts such as Ziegler–Natta, Phillips, and some supported metallocenes. This been used quantify effect conditions catalyst formulations polyolefin MWD kinetics. Related met...