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The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane

Herein, two salalen titanium(iv) complexes were synthesized and characterized. These complexes coexisted as two isomers in certain conditions and underwent isomerization, as evidenced by (1)H NMR spectroscopy. Furthermore, the molar ratio of the two isomers ranged from 100 : 15 at 30 °C to 100 : 34...

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Autores principales: Li, Sihan, Zhu, Yuqiong, Liang, Huaqing, Xie, Xiuli, Zhan, Yipeng, Liang, Guodong, Zhu, Fangming
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9076524/
https://www.ncbi.nlm.nih.gov/pubmed/35541601
http://dx.doi.org/10.1039/c9ra08899g
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author Li, Sihan
Zhu, Yuqiong
Liang, Huaqing
Xie, Xiuli
Zhan, Yipeng
Liang, Guodong
Zhu, Fangming
author_facet Li, Sihan
Zhu, Yuqiong
Liang, Huaqing
Xie, Xiuli
Zhan, Yipeng
Liang, Guodong
Zhu, Fangming
author_sort Li, Sihan
collection PubMed
description Herein, two salalen titanium(iv) complexes were synthesized and characterized. These complexes coexisted as two isomers in certain conditions and underwent isomerization, as evidenced by (1)H NMR spectroscopy. Furthermore, the molar ratio of the two isomers ranged from 100 : 15 at 30 °C to 100 : 34 at 120 °C, driven by thermal energy, based on variable temperature (1)H NMR characterization. Both complexes were employed as catalysts for ethylene polymerization in the presence of methylaluminoxane (MAO). The influence of the electronic effects of different substituent groups at the ortho position of the phenolate on ethylene polymerization behaviors, molecular weight and molecular weight distributions of the resulting polyethylene was investigated. The fluorinated salalen titanium(iv) complex revealed relatively high catalytic activity and thermal stability owing to the electron-withdrawing inductive effect. Moreover, disentangled linear polyethylene with ultrahigh molecular weight (M(w) up to 3000 kDa) and narrow molecular weight distribution (M(w)/M(n) ∼ 2) was obtained in the polymerization temperature range of 30 °C to 50 °C.
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spelling pubmed-90765242022-05-09 The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane Li, Sihan Zhu, Yuqiong Liang, Huaqing Xie, Xiuli Zhan, Yipeng Liang, Guodong Zhu, Fangming RSC Adv Chemistry Herein, two salalen titanium(iv) complexes were synthesized and characterized. These complexes coexisted as two isomers in certain conditions and underwent isomerization, as evidenced by (1)H NMR spectroscopy. Furthermore, the molar ratio of the two isomers ranged from 100 : 15 at 30 °C to 100 : 34 at 120 °C, driven by thermal energy, based on variable temperature (1)H NMR characterization. Both complexes were employed as catalysts for ethylene polymerization in the presence of methylaluminoxane (MAO). The influence of the electronic effects of different substituent groups at the ortho position of the phenolate on ethylene polymerization behaviors, molecular weight and molecular weight distributions of the resulting polyethylene was investigated. The fluorinated salalen titanium(iv) complex revealed relatively high catalytic activity and thermal stability owing to the electron-withdrawing inductive effect. Moreover, disentangled linear polyethylene with ultrahigh molecular weight (M(w) up to 3000 kDa) and narrow molecular weight distribution (M(w)/M(n) ∼ 2) was obtained in the polymerization temperature range of 30 °C to 50 °C. The Royal Society of Chemistry 2019-12-17 /pmc/articles/PMC9076524/ /pubmed/35541601 http://dx.doi.org/10.1039/c9ra08899g Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/
spellingShingle Chemistry
Li, Sihan
Zhu, Yuqiong
Liang, Huaqing
Xie, Xiuli
Zhan, Yipeng
Liang, Guodong
Zhu, Fangming
The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title_full The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title_fullStr The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title_full_unstemmed The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title_short The influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
title_sort influences of electronic effect and isomerization of salalen titanium(iv) complexes on ethylene polymerization in the presence of methylaluminoxane
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9076524/
https://www.ncbi.nlm.nih.gov/pubmed/35541601
http://dx.doi.org/10.1039/c9ra08899g
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