High-Temperature Single-Site Ethylene Polymerization Behavior of
Titanate Complexes Supported by
1,3-Bis(3,5-dialkylpyrazol-1-yl)propan-2-olate Ligation
Richard Eaves
Sean Parkin
Folami T. Ladipo
10.1021/ic701221f.s002
https://acs.figshare.com/articles/journal_contribution/High_Temperature_Single_Site_Ethylene_Polymerization_Behavior_of_Titanate_Complexes_Supported_by_1_3_Bis_3_5_dialkylpyrazol_1_yl_propan_2_olate_Ligation/2978200
Titanate(1−) complexes Na[(THF)(κ<sup>1</sup>-O-bdbpzp)TiCl<sub>4</sub>] (<b>1</b>) and Na[(THF)(κ<sup>1</sup>-O-bdmpzp)TiCl<sub>4</sub>] (<b>2</b>) and titanate(2−)
complexes [Na(THF)]<sub>2</sub>[(κ<sup>1</sup>-O-bdbpzp)<sub>2</sub>TiCl<sub>4</sub>] (<b>4</b>) and [Na(THF)]<sub>2</sub>[(κ<sup>1</sup>-O-bdmpzp)<sub>2</sub>TiCl<sub>4</sub>] (<b>5</b>) were obtained in good yield
from reaction of Na[<b>bdbpzp</b>] or Na[<b>bdmpzp</b>] (sodium salt of 1,3-bis(3,5-di-tert-butylpyrazol-1yl)propan-2-ol or 1,3-bis(3,5-dimethylpyrazol-1yl)propan-2-ol) with TiCl<sub>4</sub> (in the appropriate molar ratio) at 0−25 °C. Protonolysis of TiCl<sub>4</sub>
with 1 equiv of <b>bdmpzpH</b> furnished related zwitterionic titanate(1−) complex <b>3</b> that possessed a κ<sup>2</sup>-N,O-coordinated
pyrazolyl-alkoxide with pendant pyrazolium group. Methylalumoxane (MAO) activation of <b>1</b>−<b>5</b> under high-temperature
solution polymerization conditions produced active single-site ethylene polymerization catalysts that exhibit considerably
higher thermal stability (especially <b>2</b>/MAO, <b>3</b>/MAO, and <b>5</b>/MAO) than previously reported for Cp<sub>2</sub>TiCl<sub>2</sub>/MAO or Ti
catalysts supported by related heteroscorpionate or scorpionate ligation.
2007-10-29 00:00:00
Na
MAO
solution polymerization conditions
TiCl 4
pendant pyrazolium group