Crystal structures and stereospecific propylene polymerizations with chiral hafnium metallocene catalysts

Journal Article · Wed Oct 14 04:00:00 EDT 1987 · J. Am. Chem. Soc.; (United States)

DOI:https://doi.org/10.1021/ja00255a068· OSTI ID:5615835

Ewen, J A; Haspeslagh, L; Atwood, J L; Zhang, H

Ligand effects on stereoregulation with homogeneous catalysts have been stimulated considerable interest in Ziegler-Natta propylene polymerizations with metallocene catalysts. The major limitations to development in this area have been that the titanium catalysts are unstable at conventional polymerization temperatures, and that the zirconium analogues only produce low molecular weight oligomers in significant quantities. In this contribution, the authors describe the structures and the polymerization behavior of both rac-ethylenebis(indenyl)hafnium(IV) dichloride (rac-Et(Ind)/sub 2/HfCl/sub 2/) and rac-ethylenebis(4,5,6,7-tetrahydro-1-indenyl)hafnium(IV) dichloride (rac-Et-(IndH/sub 4/)/sub 2/HfCl/sub 2/). The results are compared to those with Ti and Zr analogues. The new Hf catalysts are the first metallocenes to provide high yields of high molecular weight isotactic polypropylene.

• Research Organization: Fina Oil and Chemical Co., Deer Park, TX
• OSTI ID: 5615835
• Journal Information: J. Am. Chem. Soc.; (United States), Journal Name: J. Am. Chem. Soc.; (United States) Vol. 109:21; ISSN JACSA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
ALKENES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHEMICAL REACTION YIELD
CHEMICAL REACTIONS
CHLORIDES
CHLORINE COMPOUNDS
DATA
EXPERIMENTAL DATA
HAFNIUM CHLORIDES
HAFNIUM COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HYDROCARBONS
INFORMATION
LIGANDS
NUMERICAL DATA
ORGANIC COMPOUNDS
POLYMERIZATION
PROPYLENE
REFRACTORY METAL COMPOUNDS
TRANSITION ELEMENT COMPOUNDS
YIELDS