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
SN - 1381-1169
IS - 1-2
ER -