A Theoretical Outlook on the Stereoselectivity Origins of Isoselective Zirconocene Propylene Polymerization Catalysts - Archive ouverte HAL Access content directly
Journal Articles Chemistry - A European Journal Year : 2018

A Theoretical Outlook on the Stereoselectivity Origins of Isoselective Zirconocene Propylene Polymerization Catalysts

Abstract

The first three insertion steps of propylene for isoselective metallocenes from the one-carbon-bridged cyclopentadienyl-fluorenyl {Cp/Flu} and silicon-bridged ansa-bis(indenyl) {SBI} families were computed by using a theoretical method implementing the B3PW91 functional in combination with solvent corrections incorporated with the Solvation Model based on Density (SMD) continuum model. For C -symmetric {Cp/Flu}-type metallocenes, two mechanisms of stereocontrol were validated theoretically: more facile and more stereoselective chain "stationary" insertion (or site epimerization backskip) and less stereoselective alternating mechanisms. For the C -symmetric {SBI}-type system, the computation results were in complete agreement with the sole operating chain migratory insertion mechanism. The thermochemical data obtained through the study were used to predict microstructures of polypropylenes by using three-parameter and one-parameter statistical models for the two metallocene systems, respectively. The calculated meso/rac pentad distributions were found to be in good agreement with those determined experimentally for isotactic polypropylene samples obtained at different polymerization temperatures.
Fichier principal
Vignette du fichier
Kirillov et al_A Theoretical Outlook on the Stereoselectivity Origins of Isoselective.pdf (1.75 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

hal-01807879 , version 1 (03-07-2018)

Identifiers

Cite

Ludovic Castro, Gabriel Theurkauff, Aurelien Vantomme, Alexandre Welle, Luc Haspeslagh, et al.. A Theoretical Outlook on the Stereoselectivity Origins of Isoselective Zirconocene Propylene Polymerization Catalysts. Chemistry - A European Journal, 2018, 24 (42), pp.10784-10792. ⟨10.1002/chem.201801438⟩. ⟨hal-01807879⟩
115 View
165 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More