891787-27-2Relevant academic research and scientific papers
Preparation, structure and ethylene polymerization/oligomerization behavior of 2-carbethoxy-6-iminopyridine-based transition metal complexes
Su, Bi-Yun,Zhao, Jian-She
, p. 3289 - 3298 (2008/10/09)
The synthesis, characterization and ethylene polymerization/oligomerization of a series of transition metal complexes with the formula {2-carbethoxy-6-[1-[(2,6-dimethylphenyl)imino]-ethyl]pyridine}nMCl2 [M = Mn(II) (8), Fe(II) (9), Co(II) (10), Cu(II) (11), Zn(II) (12), n = 1; Ni(II) (13), n = 2]; {2-carbethoxy-6-[1-[(2,4,6- trimethylphenyl)imino]ethyl]pyridine}MCl2 [M = Fe(II) (14), Co(II) (15), Ni(II) (16)]; {2-carbethoxy-6-[1-[(2,6-diethylphenyl)-imino]ethyl]pyridine}MCl2 [M = Fe(II) (17), Co(II) (18), Ni(II) (19)] have been reported. Systematic studies are focused on the relationship between the catalytic activity of these complexes for ethylene polymerization/oligomerization and the electronic property of the central metal, the ligand structure, as well as the reaction conditions. The Fe(II), Co(II), Ni(II) catalyst systems afford moderate activities ranging from 0.35 × 104 to 5.9 × 104 g/mol-Metal h atm, and the most active catalysts are those with two smaller substituents in the ortho-positions of the N-aryl ring. X-ray crystallographic analysis of complex 12 reveals a four-coordinated distorted tetrahedral geometry, while complex 18 indicates a five-coordinated distorted trigonal bipyramid, in which the tridentate ligand coordinates via weak bonding between the carbonyl oxygen of the ester group and cobalt.
