Models for intermediates in metallocene-catalyzed alkene polymerization: Alkene dissociation from Cp2Zr[eta(1) eta(2)-CH2Si(CH3)(2)CH2CH=CH2][B(C6F5)(4)]

Authors
Casey, CP Carpenetti, DW Sakurai, H
Citation
Cp. Casey et al., Models for intermediates in metallocene-catalyzed alkene polymerization: Alkene dissociation from Cp2Zr[eta(1) eta(2)-CH2Si(CH3)(2)CH2CH=CH2][B(C6F5)(4)], ORGANOMETAL, 20(20), 2001, pp. 4262-4265
Citations number
41
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
ORGANOMETALLICS
ISSN journal
02767333 → ACNP
Volume
20
Issue
20
Year of publication
2001
Pages
4262 - 4265
Database
ISI
SICI code
0276-7333(20011001)20:20<4262:MFIIMA>2.0.ZU;2-D
Abstract
The bis(allyldimethylsilylmethyl)bis(cyclopentadienyl)zirconium complex Cp2 Zr[CH2Si-(CH3)(2)CH2CH=CH2](2) (5) reacted rapidly with [(C6H5)(2)(CH3)NH] [B(C6F5)(4)] in CD2Cl2 at - 78 degreesC to form the cationic zirconium- alk yl-alkene complex Cp2Zr[eta (1), eta (2)-CH2Si(CH3)(2)CH2CH= CH2] [B(C6F5)( 4)] (6). Low-temperature H-1 and C-13 NMR spectroscopy established the coor dination of the tethered alkene to the d(0) metal center. Line shape analys is of the coalescence of the diastereotopic Cp ligand resonances allowed me asurement of the alkene dissociation energy barrier [DeltaG(double dagger)( -28 degreesC) = 12.7 +/- 0.8 kcal mol(-1)].