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Vinyl polymerization of norbornene by nickel(II) complexes bearing β‐diketiminate ligands
Author(s) -
Li Yongfei,
Gao Meili,
Wu Qing
Publication year - 2007
Publication title -
applied organometallic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.53
H-Index - 71
eISSN - 1099-0739
pISSN - 0268-2605
DOI - 10.1002/aoc.1323
Subject(s) - norbornene , chemistry , methylaluminoxane , nickel , steric effects , catalysis , bromide , polymerization , polymer chemistry , aryl , ligand (biochemistry) , vinyl bromide , medicinal chemistry , stereochemistry , metallocene , organic chemistry , alkyl , receptor , biochemistry , polymer
Norbornene polymerizations were carried out using nickel(II) bromide complexes CH{C(R)NAr} 2 NiBr ( 1 , R = CH 3 , Ar = 2, 6 − i Pr 2 C 6 H 3 ; 2 , R = CH 3 , Ar = 2, 6‐Me 2 C 6 H 3 ; 3 , R = CF 3 , Ar = 2, 6 − i Pr 2 C 6 H 3 ; 4 , R = CF 3 , Ar = 2, 6‐Me 2 C 6 H 3 ) in the presence of methylaluminoxane. Compound 3 is the most active norbornene polymerization catalyst of all the nickel complexes tested. The activity of theses catalysts increases with increases in steric bulk of the substituents on the aryl rings. The electronic nature of the ligand backbone also affects the activity. The resulting polynorbornenes are vinyl type by IR and NMR analyses. Copyright © 2007 John Wiley & Sons, Ltd.