TY - JOUR
T1 - Vinyl-addition polymerization of norbornene catalyzed by (pyrazol-1-ylmethyl)pyridine divalent iron, cobalt and nickel complexes
AU - Benade, Letitia L.
AU - Ojwach, Stephen O.
AU - Obuah, Collins
AU - Guzei, Ilia A.
AU - Darkwa, James
PY - 2011/11/3
Y1 - 2011/11/3
N2 - Complexes of 2-((3,5-dimethyl)-1H-pyrazol-1-ylmethyl)pyridine (L1), 2-((3,5-ditert-butyl-1H-pyrazol-1-yl)methyl)pyridine (L2), 2-((3,5-diphenyl)-1H- pyrazol-1-yl)methyl)pyridine (L3), 2-((3,5-bis(trifluoromethyl)-1H-pyrazol-1- ylmethyl)pyridine (L4) and 2,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)methyl)pyridine (L5) with cobalt(II), iron(II) and nickel(II), Ni(L1)Cl2 (1), Co(L1)Cl2 (2), Fe(L1)Cl2 (3), Ni(L2)Cl2 (4), Ni(L3)Cl2 (5), Co(L3)Cl2 (6), Fe(L3)Cl2 (7), Ni(L4)Cl2 (8) and Ni(L5)Cl2 (9), were used as catalyst precursors to produce vinyl-addition type norbornene polymers. Both the identity of the metal center and nature of ligand affected the polymerization behaviour of the resultant catalysts. Nickel catalysts were generally more active than the corresponding iron and cobalt analogues. The polynorbornene produced have high molecular weights (0.5-2.1 × 106 g/mol) and narrow molecular weight distributions. Analyses of polymer microstructure using NMR and IR spectroscopy confirmed the polymers produced to be vinyl-addition polynorbornene.
AB - Complexes of 2-((3,5-dimethyl)-1H-pyrazol-1-ylmethyl)pyridine (L1), 2-((3,5-ditert-butyl-1H-pyrazol-1-yl)methyl)pyridine (L2), 2-((3,5-diphenyl)-1H- pyrazol-1-yl)methyl)pyridine (L3), 2-((3,5-bis(trifluoromethyl)-1H-pyrazol-1- ylmethyl)pyridine (L4) and 2,6-bis(3,5-dimethyl-1H-pyrazol-1-yl)methyl)pyridine (L5) with cobalt(II), iron(II) and nickel(II), Ni(L1)Cl2 (1), Co(L1)Cl2 (2), Fe(L1)Cl2 (3), Ni(L2)Cl2 (4), Ni(L3)Cl2 (5), Co(L3)Cl2 (6), Fe(L3)Cl2 (7), Ni(L4)Cl2 (8) and Ni(L5)Cl2 (9), were used as catalyst precursors to produce vinyl-addition type norbornene polymers. Both the identity of the metal center and nature of ligand affected the polymerization behaviour of the resultant catalysts. Nickel catalysts were generally more active than the corresponding iron and cobalt analogues. The polynorbornene produced have high molecular weights (0.5-2.1 × 106 g/mol) and narrow molecular weight distributions. Analyses of polymer microstructure using NMR and IR spectroscopy confirmed the polymers produced to be vinyl-addition polynorbornene.
KW - Cobalt
KW - Iron
KW - Nickel catalysts
KW - Norbornene polymerization
KW - Structures
UR - http://www.scopus.com/inward/record.url?scp=80053941494&partnerID=8YFLogxK
U2 - 10.1016/j.poly.2011.08.021
DO - 10.1016/j.poly.2011.08.021
M3 - Article
AN - SCOPUS:80053941494
SN - 0277-5387
VL - 30
SP - 2878
EP - 2883
JO - Polyhedron
JF - Polyhedron
IS - 17
ER -