Pyridinylimine-based nickel(II) and palladium(II) complexes: preparation, structural characterization and use as alkene polymerization catalysts

• Published in: Journal of organometallic chemistry Vol. 606; no. 2; pp. 112 - 124
• Main Authors: Laine, Timo V, Piironen, Ulla, Lappalainen, Kristian, Klinga, Martti, Aitola, Erkki, Leskelä, Markku
• Format: Journal Article
• Language: English
• Published: LAUSANNE Elsevier B.V 28.07.2000; Elsevier
• Subjects: Catalysis; Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Crystal structures; Ethylene; Nickel; Nitrogen ligand; Norbornene; Palladium; Physical Sciences; Polymerization; Science & Technology; Crystal structures; Ethylene; Polymerization; Nickel; Palladium; Catalysis; Norbornene; Nitrogen ligand; nickel; polymerization; VINYLIC POLYMERIZATION; norbornene; nitrogen ligand; OLEFIN POLYMERIZATION; catalysis; crystal structures; ethylene; NORBORNENE DERIVATIVES; ETHYLENE POLYMERIZATION; (ETA-ALLYL)PALLADIUM(II); ALPHA-DIIMINE CATALYSTS; ADDITION POLYMERIZATION; palladium; FUNCTIONAL-GROUPS; LATE TRANSITION-METALS; OLIGOMERIZATION
• ISSN: 0022-328X; 1872-8561
• DOI: 10.1016/S0022-328X(00)00291-6

Preparation of four dimeric nickel(II) complexes and three monomeric palladium(II) complexes bearing didentate pyridinylimine ligands is described. The solid-state structures of these compounds have been determined by single-crystal X-ray diffraction. After activation with methylaluminoxane (MAO) the nickel compounds were used as catalysts in ethylene polymerization producing nearly linear or primarily methyl-branched polymers. The effect of ligand environment was most evident on degree of branching, while catalytic activity and molecular weight of the polymer were more dependent on the general catalyst composition as well as reaction conditions. Activation of the dichloropalladium(II) complexes with MAO yields highly active catalysts for the polymerization of bicyclo[2.2.1]hept-2-ene (norbornene) whereas only low conversions (<20%) were achieved with cationic compounds obtained from two of the neutral palladium complexes by reaction with AgBF 4.