Polymerization of Propene with Modified Constrained Geometry Complexes. Double-Bond Isomerization in Pendant Alkenyl Groups Attached to Cyclopentadienyl

0181665 - UFCH-W 20030091 RIV CZ eng J - Journal Article
Staal, O. K. B. - Beetstra, D. J. - Jekel, A. P. - Hessen, B. - Teuben, J. H. - Štěpnička, P. - Gyepes, R. - Horáček, Michal - Pinkas, Jiří - Mach, Karel
Polymerization of Propene with Modified Constrained Geometry Complexes. Double-Bond Isomerization in Pendant Alkenyl Groups Attached to Cyclopentadienyl.
Collection of Czechoslovak Chemical Communications. Roč. 68, - (2003), s. 1119-1130. ISSN 0010-0765
R&D Projects: GA AV ČR IBS4040017; GA ČR GA203/02/0436
Institutional research plan: CEZ:AV0Z4040901
Keywords : titanium * CGC catalysts * propene polymerization
Subject RIV: CF - Physical ; Theoretical Chemistry
Impact factor: 1.041, year: 2003

Polymerization of propene with dimethylsilylene-bridged (amidocyclopentadienyl) dichlorotitanium( IV) complexes [TiCl2 {eta(5)-1-(t-BuSiMe2N-kappaN)- 2,3,4- Me-3 -5- R-C-5}], where R =Me (1), H (2), Ph (3), 4-fluorophenyl (4), but-2-en-2-yl (5), and butyl (6), combined with excess methylaluminoxane revealed a moderate effect of the substituent R on the catalyst activity and the molecular weight of polypropene. The asymmetric substitution in the position adjacent to the bridging carbon atom resulted in polymer yields decreasing in the order 1 > 6 > 3 approximate to 5 > 4 > 2 while polymers with the molecular weights (M-w) close to 2.5 x 10(5) for 1, 3, and 4, 1.5 x 10(5) for 5 and 6, and 7.5 x 10(4) for 2 were obtained. The C-13 NMR analysis of the polymers has shown that atactic polypropene is slightly enriched with syndiotactic triads for all the catalysts. Investigation of the crystal structure of 5 by X-ray crystallography revealed that the double bond.
Permanent Link: http://hdl.handle.net/11104/0078199