2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene

Rong Gao; Kefeng Wang; Yan Li; Fosong Wang; Wen-Hua Sun; Carl Redshaw; Manfred Bochmann

doi:10.1016/j.molcata.2009.05.021

2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene

Rong Gao, Kefeng Wang, Yan Li, Fosong Wang, Wen-Hua Sun, Carl Redshaw, Manfred Bochmann

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

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Abstract

A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar=2,6-Me₂C₆H₃), Co2 (Ar=2,6-Et₂C₆H₃) and Co7 (Ar=2,6-Br₂C₆H₃) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters.

Original language	English
Pages (from-to)	166-171
Number of pages	6
Journal	Journal of Molecular Catalysis A: Chemical
Volume	309
Issue number	1-2
DOIs	https://doi.org/10.1016/j.molcata.2009.05.021
Publication status	Published - Jun 2009

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10.1016/j.molcata.2009.05.021

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@article{2c46da41981c4dfa8b52280dafd9bfc9,

title = "2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene",

abstract = "A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar=2,6-Me2C6H3), Co2 (Ar=2,6-Et2C6H3) and Co7 (Ar=2,6-Br2C6H3) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters.",

author = "Rong Gao and Kefeng Wang and Yan Li and Fosong Wang and Wen-Hua Sun and Carl Redshaw and Manfred Bochmann",

year = "2009",

month = jun,

doi = "10.1016/j.molcata.2009.05.021",

language = "English",

volume = "309",

pages = "166--171",

journal = "Journal of Molecular Catalysis A: Chemical",

publisher = "Elsevier",

number = "1-2",

}

TY - JOUR

T1 - 2-Benzoxazolyl-6-(1-(arylimino)ethyl)pyridyl cobalt (II) chlorides: A temperature switch catalyst in oligomerization and polymerization of ethylene

AU - Gao, Rong

AU - Wang, Kefeng

AU - Li, Yan

AU - Wang, Fosong

AU - Sun, Wen-Hua

AU - Redshaw, Carl

AU - Bochmann, Manfred

PY - 2009/6

Y1 - 2009/6

N2 - A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar=2,6-Me2C6H3), Co2 (Ar=2,6-Et2C6H3) and Co7 (Ar=2,6-Br2C6H3) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters.

AB - A series of cobalt (II) complexes ligated by 2-(2-benzoxazolyl)-6-(1-(arylimino)ethyl)pyridines was synthesized and characterized by FT-IR spectroscopic and elemental analysis. The molecular structures of Co1 (Ar=2,6-Me2C6H3), Co2 (Ar=2,6-Et2C6H3) and Co7 (Ar=2,6-Br2C6H3) were determined by single-crystal X-ray diffraction. Compounds Co1 and Co2 display a distorted trigonal-bipyramidal geometry, whereas complex Co7 is a distorted square-pyramid. Upon activation with methylaluminoxane (MAO), all cobalt complexes showed reactivity towards ethylene. There was however an unexpected temperature dependence; whereas, at room temperature oligomerization was observed, giving 1-alkenes with high selectivities, at elevated temperatures polyethylene was produced. This unusual catalytic behavior of the new complexes was investigated in detail under various reaction parameters.

U2 - 10.1016/j.molcata.2009.05.021

DO - 10.1016/j.molcata.2009.05.021

M3 - Article

VL - 309

SP - 166

EP - 171

JO - Journal of Molecular Catalysis A: Chemical

JF - Journal of Molecular Catalysis A: Chemical

IS - 1-2

ER -