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Vinyl polymerizations of norbornene catalyzed by nickel complexes with acetoacetamide ligands
Author(s) -
Feng Qian,
Chen Dajun,
Feng Danyang,
Jiao Libin,
Peng Zhigang,
Pei Lixia
Publication year - 2014
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.3067
Subject(s) - methylaluminoxane , chemistry , norbornene , nickel , steric effects , catalysis , ligand (biochemistry) , crystal structure , polymer chemistry , nuclear magnetic resonance spectroscopy , molecule , stereochemistry , polymer , metallocene , polymerization , crystallography , organic chemistry , biochemistry , receptor
On the basis of a remote effect, a series of acetoacetamide ligands and corresponding nickel complexes N ‐(R‐phenyl) acetoacetamide Ni(CH 2 Ph) (PMe 3 ) (R = H, 1 ; R = 2‐methyl, 2 ; R = 2,6‐dimethyl, 3 ; R = 2,6‐diisopropyl, 4 ; R = 4‐NO 2 , 5 ) were synthesized and characterized. The solid structure of complex 3 was confirmed by X‐ray single‐crystal analysis to be of cis form. 1 H and 31 P NMR spectroscopy confirmed that cis and trans isomers of nickel complexes were present in solution. Norbornene polymerizations with acetoacetamide nickel complexes activated with modified methylaluminoxane (MMAO) were investigated in detail. Remote steric and electronic effects of acetoacetamide ligand on catalytic activity and molecular weight of polynorbornenes (PNBs) were observed. Characterizations of the obtained PNBs show that the obtained polymer products are non‐crystalline vinylic‐addition polynorbornenes. Copyright © 2013 John Wiley & Sons, Ltd.