Syntheses, structure and ethylene polymerization behavior of β-diiminato titanium complexes

Li Ming Tang; Yi Qun Duan; Xiao Fang Li; Yue Sheng Li

doi:10.1016/j.jorganchem.2005.12.053

Syntheses, structure and ethylene polymerization behavior of β-diiminato titanium complexes

Li Ming Tang, Yi Qun Duan, Xiao Fang Li, Yue Sheng Li

School of Chemistry and Chemical Engineering

Research output: Contribution to journal › Article › peer-review

49 Citations (Scopus)

Abstract

A series of new titanium complexes bearing β-diiminato ligands [(Ph)NC(R₁)CHC(R₂)N(Ph)]₂TiCl₂ (4a: R₁ = R₂ = CH₃; 4b: R₁ = R ₂ = CF₃; 4c: R₁ = Ph, R₂ = CH ₃; 4d: R₁ = Ph, R₂ = CF₃) has been synthesized and characterized. X-ray crystal structures reveal that complexes 4a and 4c adopt distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4a-d are active catalysts for ethylene polymerization, and produce high molecular weight polyethylenes. Catalyst activities and the molecular weights of polymers are considerably influenced by the steric and electronic effects of substituents on the catalyst backbone under the same polymerization condition. With the strong electron-withdrawing groups (CF₃) at R₁ or/and R ₂ position, complexes 4b and 4d show higher activities than complexes 4a and 4c, respectively.

Original language	English
Pages (from-to)	2023-2030
Number of pages	8
Journal	Journal of Organometallic Chemistry
Volume	691
Issue number	9
DOIs	https://doi.org/10.1016/j.jorganchem.2005.12.053
Publication status	Published - 15 Apr 2006

Keywords

Catalyst
Ethylene
Polymerization
Titanium complex

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10.1016/j.jorganchem.2005.12.053

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title = "Syntheses, structure and ethylene polymerization behavior of β-diiminato titanium complexes",

abstract = "A series of new titanium complexes bearing β-diiminato ligands [(Ph)NC(R1)CHC(R2)N(Ph)]2TiCl2 (4a: R1 = R2 = CH3; 4b: R1 = R 2 = CF3; 4c: R1 = Ph, R2 = CH 3; 4d: R1 = Ph, R2 = CF3) has been synthesized and characterized. X-ray crystal structures reveal that complexes 4a and 4c adopt distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4a-d are active catalysts for ethylene polymerization, and produce high molecular weight polyethylenes. Catalyst activities and the molecular weights of polymers are considerably influenced by the steric and electronic effects of substituents on the catalyst backbone under the same polymerization condition. With the strong electron-withdrawing groups (CF3) at R1 or/and R 2 position, complexes 4b and 4d show higher activities than complexes 4a and 4c, respectively.",

keywords = "Catalyst, Ethylene, Polymerization, Titanium complex",

author = "Tang, {Li Ming} and Duan, {Yi Qun} and Li, {Xiao Fang} and Li, {Yue Sheng}",

year = "2006",

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doi = "10.1016/j.jorganchem.2005.12.053",

language = "English",

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T1 - Syntheses, structure and ethylene polymerization behavior of β-diiminato titanium complexes

AU - Tang, Li Ming

AU - Duan, Yi Qun

AU - Li, Xiao Fang

AU - Li, Yue Sheng

PY - 2006/4/15

Y1 - 2006/4/15

N2 - A series of new titanium complexes bearing β-diiminato ligands [(Ph)NC(R1)CHC(R2)N(Ph)]2TiCl2 (4a: R1 = R2 = CH3; 4b: R1 = R 2 = CF3; 4c: R1 = Ph, R2 = CH 3; 4d: R1 = Ph, R2 = CF3) has been synthesized and characterized. X-ray crystal structures reveal that complexes 4a and 4c adopt distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4a-d are active catalysts for ethylene polymerization, and produce high molecular weight polyethylenes. Catalyst activities and the molecular weights of polymers are considerably influenced by the steric and electronic effects of substituents on the catalyst backbone under the same polymerization condition. With the strong electron-withdrawing groups (CF3) at R1 or/and R 2 position, complexes 4b and 4d show higher activities than complexes 4a and 4c, respectively.

AB - A series of new titanium complexes bearing β-diiminato ligands [(Ph)NC(R1)CHC(R2)N(Ph)]2TiCl2 (4a: R1 = R2 = CH3; 4b: R1 = R 2 = CF3; 4c: R1 = Ph, R2 = CH 3; 4d: R1 = Ph, R2 = CF3) has been synthesized and characterized. X-ray crystal structures reveal that complexes 4a and 4c adopt distorted octahedral geometry around the titanium center. With modified methylaluminoxane (MMAO) as a cocatalyst, complexes 4a-d are active catalysts for ethylene polymerization, and produce high molecular weight polyethylenes. Catalyst activities and the molecular weights of polymers are considerably influenced by the steric and electronic effects of substituents on the catalyst backbone under the same polymerization condition. With the strong electron-withdrawing groups (CF3) at R1 or/and R 2 position, complexes 4b and 4d show higher activities than complexes 4a and 4c, respectively.

KW - Catalyst

KW - Ethylene

KW - Polymerization

KW - Titanium complex

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DO - 10.1016/j.jorganchem.2005.12.053

M3 - Article

AN - SCOPUS:33645405016

SN - 0022-328X

VL - 691

SP - 2023

EP - 2030

JO - Journal of Organometallic Chemistry

JF - Journal of Organometallic Chemistry

IS - 9

ER -

Syntheses, structure and ethylene polymerization behavior of β-diiminato titanium complexes

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Keywords

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