| Autor: |
Jones, R. L., Elder, M. J., Ewen, J. A. |
| Předmět: |
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| Zdroj: |
Phosphorus, Sulfur & Silicon & the Related Elements; Mar/Apr2005, Vol. 180 Issue 3/4, p827-843, 17p, 4 Diagrams, 4 Charts, 2 Graphs |
| Abstrakt: |
Substituted metallocene ligands containing cyclopentadiene ring fused to either selenophene or benzo[b]tellurophene were prepared following methods previously developed for analogs containing sulfur. 5-Methyl-4,5-dihydro-cyclopenta[b]-selenophen-6-one (2) and 3-Methyl-3,4-dihydro-benzo[b]cyclopenta[d]telluraphen-2-one (7) (major isomers) were prepared by polyphosphoric acid catalyzed Friedel-Crafts acylation/Nazarov cyclization of methacrylic acid onto selenophene and respectively benzo[b]tellurophene. Following reduction of the ketone to alcohol, then dehydration, the chalcogen-containing cyclopentadiene olefins were prepared. The olefins were deprotonated with n-butyllithium followed by either bridging with dichlorodimethylsilane, deprotonation and metallation, or deprotonation and direct metallation. In this manner, isomeric mixtures of –rac/-meso dimethylsilanediylbis(? 5 -5-Methyl-cyclopenta[b]selenophen-yl)zirconium dichloride (5) Bis(? 5- 2-methyl-cyclopenta[b][1]benzotelluraphen-yl)zirconium dichloride (9) were prepared and characterized. Complexes formed active olefin polymerization catalyst when activated with methylalumoxane. Polymerization results with ethylene and propylene are included. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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