External silane donors in Ziegler-Natta catalysis. Computerbased molecular model calculations on alkoxysilanes

M. Härkönen (Corresponding Author), Lauri Kuutti, J. V. Seppälä

Research output: Contribution to journalArticleScientific

Abstract

The electronic factors of external alkoxysilane donors used in modern Ziegler-Natta catalyst systems were estimated by quantum mechanical MNDO (modified neglect of diatomic overlap) calculations on model compounds. The calculated electron densities of oxygen atoms in alkoxy groups were plotted against the experimental activity and the isotacticity of propene polymerization. The steric hindrance and the volume of the compounds were investigated as structural factors important to the polymerization. The results indicate that the performance of the external alkoxysilane donor is affected by both electronic and structural factors. The average electron density around the electron-donating oxygens has some influence on the deactivating power of the donor, but when the hydrocarbon part is sterically large the sterical effects apparently dominate.
Original languageEnglish
Pages (from-to)1413-1421
JournalDie Makromolekulare Chemie
Volume193
Issue number6
DOIs
Publication statusPublished - 1992
MoE publication typeB1 Article in a scientific magazine

Fingerprint

Silanes
silanes
Catalysis
catalysis
Carrier concentration
Polymerization
Oxygen
polymerization
Hydrocarbons
Ziegler catalyst
Propylene
electronics
Atoms
Catalysts
Electrons
oxygen atoms
hydrocarbons
oxygen
electrons
alkoxyl radical

Cite this

@article{66b454a0978746589b24234185b2eb05,
title = "External silane donors in Ziegler-Natta catalysis. Computerbased molecular model calculations on alkoxysilanes",
abstract = "The electronic factors of external alkoxysilane donors used in modern Ziegler-Natta catalyst systems were estimated by quantum mechanical MNDO (modified neglect of diatomic overlap) calculations on model compounds. The calculated electron densities of oxygen atoms in alkoxy groups were plotted against the experimental activity and the isotacticity of propene polymerization. The steric hindrance and the volume of the compounds were investigated as structural factors important to the polymerization. The results indicate that the performance of the external alkoxysilane donor is affected by both electronic and structural factors. The average electron density around the electron-donating oxygens has some influence on the deactivating power of the donor, but when the hydrocarbon part is sterically large the sterical effects apparently dominate.",
author = "M. H{\"a}rk{\"o}nen and Lauri Kuutti and Sepp{\"a}l{\"a}, {J. V.}",
year = "1992",
doi = "10.1002/macp.1992.021930617",
language = "English",
volume = "193",
pages = "1413--1421",
journal = "Macromolecular Chemistry and Physics",
issn = "1022-1352",
publisher = "Wiley-VCH Verlag",
number = "6",

}

External silane donors in Ziegler-Natta catalysis. Computerbased molecular model calculations on alkoxysilanes. / Härkönen, M. (Corresponding Author); Kuutti, Lauri; Seppälä, J. V.

In: Die Makromolekulare Chemie, Vol. 193, No. 6, 1992, p. 1413-1421.

Research output: Contribution to journalArticleScientific

TY - JOUR

T1 - External silane donors in Ziegler-Natta catalysis. Computerbased molecular model calculations on alkoxysilanes

AU - Härkönen, M.

AU - Kuutti, Lauri

AU - Seppälä, J. V.

PY - 1992

Y1 - 1992

N2 - The electronic factors of external alkoxysilane donors used in modern Ziegler-Natta catalyst systems were estimated by quantum mechanical MNDO (modified neglect of diatomic overlap) calculations on model compounds. The calculated electron densities of oxygen atoms in alkoxy groups were plotted against the experimental activity and the isotacticity of propene polymerization. The steric hindrance and the volume of the compounds were investigated as structural factors important to the polymerization. The results indicate that the performance of the external alkoxysilane donor is affected by both electronic and structural factors. The average electron density around the electron-donating oxygens has some influence on the deactivating power of the donor, but when the hydrocarbon part is sterically large the sterical effects apparently dominate.

AB - The electronic factors of external alkoxysilane donors used in modern Ziegler-Natta catalyst systems were estimated by quantum mechanical MNDO (modified neglect of diatomic overlap) calculations on model compounds. The calculated electron densities of oxygen atoms in alkoxy groups were plotted against the experimental activity and the isotacticity of propene polymerization. The steric hindrance and the volume of the compounds were investigated as structural factors important to the polymerization. The results indicate that the performance of the external alkoxysilane donor is affected by both electronic and structural factors. The average electron density around the electron-donating oxygens has some influence on the deactivating power of the donor, but when the hydrocarbon part is sterically large the sterical effects apparently dominate.

U2 - 10.1002/macp.1992.021930617

DO - 10.1002/macp.1992.021930617

M3 - Article

VL - 193

SP - 1413

EP - 1421

JO - Macromolecular Chemistry and Physics

JF - Macromolecular Chemistry and Physics

SN - 1022-1352

IS - 6

ER -