Influence of the ligand structure of hafnocene polymerization catalysts: A theoretical study on chain termination reactions in ethene polymerization
| Autor: | John Severn, Esa Kokko, Päivi Pitkänen, Tapani A. Pakkanen, Janne Maaranen, Anneli Pakkanen, Mikko Linnolahti, Virve A. Karttunen |
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| Rok vydání: | 2008 |
| Předmět: |
Ligand
Organic Chemistry Radical polymerization Photochemistry Chain termination Biochemistry Inorganic Chemistry chemistry.chemical_compound Monomer chemistry Polymerization Hydrogenolysis Ab initio quantum chemistry methods Materials Chemistry Living polymerization Physical and Theoretical Chemistry |
| Zdroj: | Journal of Organometallic Chemistry. 693:3915-3922 |
| ISSN: | 0022-328X |
| DOI: | 10.1016/j.jorganchem.2008.09.070 |
| Popis: | Ligand effects on chain termination reactions in hafnocene-catalyzed ethene polymerization process have been systematically studied by quantum chemical methods. β-hydrogen transfer to metal, β-hydrogen transfer to monomer and hydrogenolysis were studied for 27 hafnocenes, initiating the chain termination reactions after insertion of the second ethene monomer. The results of the calculations were studied as a function of the ligand structure, focusing on the effects of various ancillary ligands, ligand substituents and bridging units. The ligand effects on chain termination reactions are strongly affected by combined effects of various structural units, in particular, in the cases of β-hydrogen transfer to monomer and hydrogenolysis. The results are expected to aid in design and development of new hafnocene polymerization catalysts. |
| Databáze: | OpenAIRE |
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