Role(s) of TMA in polymerization

CATEGORY: POLYMERIZATION
Role(s) of TMA in polymerization

Type	Journal Article
Author	C. Ehm
Author	R. Cipullo
URL	http://pubs.rsc.org/en/content/articlelanding/2016/dt/c5dt04895h
Volume	45
Issue	16
Pages	6847-6855
Publication	Dalton Transactions
Date	2016.04.19
Abstract	Quenched-flow data for propene polymerization with rac-Me2Si(2-Me-4-Ph-1-indenyl)2ZrCl2/MAO support a picture where removal of MAO qualitatively changes the kinetic profile from a mainly enthalpic to a mainly entropic barrier. DFT studies suggest that a not previously recognized singly-bridged end-on coordination mode of Me6Al2 to catalytically active centers may be kinetically relevant as a resting state. In contrast, the more traditional doubly-bridged complex of Me3Al is proposed to be more relevant to chain transfer to cocatalyst.