TY - JOUR
T1 - Synthesis, characterization, and ethylene oligomerization and polymerization of ferrous and cobaltous 2-(ethylcarboxylato)-6-iminopyridyl complexes
AU - Sun, Wen Hua
AU - Tang, Xiubo
AU - Gao, Tielong
AU - Wu, Biao
AU - Zhang, Wenjuan
AU - Ma, Hongwei
PY - 2004/10/11
Y1 - 2004/10/11
N2 - A series of ferrous complexes (L)FeCl 2 (3a-f) and cobaltous complexes (L)CoCl 2 (4a-f) were prepared by the reaction of 2-(carboxylato)-6-iminopyridines 2a-f (2-COOEt-6-(2,6-R 2C 6H 3N=CCH 3)C 5H 3N: 2a, R = CH 3; 2b, R = Et; 2c, R = i-Pr; 2d, R = F; 2e, R = Cl; 2f, R = Br) with FeCl 2 or Coda. The obtained complexes were characterized by elemental analysis and IR spectroscopy, and the solid-state structures of 2b,c, 3b,c,e,f, and 4c,f were determined by X-ray diffraction analysis. X-ray crystallographic analyses of complexes 3c,e,f and 4c,f reveal a four-coordinated distorted-tetrahedral geometry, except for complex 3b, in which the tridentate ligand is coordinated through a weak bonding between iron and the carbonyl oxygen of the ester group. The complexes were studied for ethylene oligomerization and polymerization in the presence of methylaluminoxane (MAO) under various reaction conditions. It was found that the ferrous complexes exhibit higher activities for ethylene polymerization than for oligomerization, while the cobaltous complexes show higher activities for ethylene oligomerization. In addition, the ferrous catalytic systems predominantly produce linear oligomers and polyethylene with unsaturated end groups.
AB - A series of ferrous complexes (L)FeCl 2 (3a-f) and cobaltous complexes (L)CoCl 2 (4a-f) were prepared by the reaction of 2-(carboxylato)-6-iminopyridines 2a-f (2-COOEt-6-(2,6-R 2C 6H 3N=CCH 3)C 5H 3N: 2a, R = CH 3; 2b, R = Et; 2c, R = i-Pr; 2d, R = F; 2e, R = Cl; 2f, R = Br) with FeCl 2 or Coda. The obtained complexes were characterized by elemental analysis and IR spectroscopy, and the solid-state structures of 2b,c, 3b,c,e,f, and 4c,f were determined by X-ray diffraction analysis. X-ray crystallographic analyses of complexes 3c,e,f and 4c,f reveal a four-coordinated distorted-tetrahedral geometry, except for complex 3b, in which the tridentate ligand is coordinated through a weak bonding between iron and the carbonyl oxygen of the ester group. The complexes were studied for ethylene oligomerization and polymerization in the presence of methylaluminoxane (MAO) under various reaction conditions. It was found that the ferrous complexes exhibit higher activities for ethylene polymerization than for oligomerization, while the cobaltous complexes show higher activities for ethylene oligomerization. In addition, the ferrous catalytic systems predominantly produce linear oligomers and polyethylene with unsaturated end groups.
UR - http://www.scopus.com/inward/record.url?scp=6344278692&partnerID=8YFLogxK
U2 - 10.1021/om0496636
DO - 10.1021/om0496636
M3 - Article
AN - SCOPUS:6344278692
SN - 0276-7333
VL - 23
SP - 5037
EP - 5047
JO - Organometallics
JF - Organometallics
IS - 21
ER -