Precision Chain-Walking Polymerization of trans-4-Octene Catalyzed by α-Diimine Nickel(II) Catalysts Bearing ortho-sec-Phenethyl Groups.
α-Diimine nickel complexes bearing bulky ortho-sec-phenethyl groups (bis{[N,N'-(4-methyl-2,6-di-sec-phenethylphenyl)imino]-1,2-dimethylethane}dibromonickel (1), bis{[N,N'-(4,6-dimethyl-2-sec-phenethylphenyl)imino]-1,2-dimethylethane}dibromonickel (2), bis{[N,N'-(4-methyl-2-sec-phenethylphenyl)imino]-1,2-dimethylethane}dibromonickel (3)) and {bis[N,N'-(2,4,6-trimethylphenyl)imino]-1,2-dimethylethane}dibromidonickel (4) are used as a precatalyst for the polymerization of trans-4-octene upon activation with modified methylaluminoxane. These catalysts conduct chain-walking polymerization of trans-4-octene to give polymers possessing propyl and butyl branches with high molecular weight and narrow molecular weight distribution. The branching structure depends on the nickel complex as well as the polymerization temperature, and the ratio of propyl branch was increased with increasing the bulkiness of the ligand and decreasing the polymerization temperature. Consequently, the most bulky 1 among the complexes used is found to polymerize trans-4-octene with high 1,5-regioselectivity at -20 °C to give poly(1-propylpentan-1,5-diyl).
Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan.
Fuzhou
F
Wang
Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan.
Ryo
R
Tanaka
State Key Lab of Chemical Fibers and Polymer Materials, College of Material Science and Engineering, Donghua University, Shanghai, 201620, China.
Zhengguo
Z
Cai
Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan.
Yuushou
Y
Nakayama
Graduate School of Engineering, Hiroshima University, Kagamiyama 1-4-1, Higashi-Hiroshima, 739-8527, Japan.
Takeshi
T
Shiono
D000475:Alkenes / Q000737:chemistry*; D001593:Benzyl Compounds / Q000737:chemistry*; D002384:Catalysis; D007097:Imines / Q000737:chemistry*; D008970:Molecular Weight; D009532:Nickel / Q000737:chemistry*; D058105:Polymerization; D013237:Stereoisomerism; D013696:Temperature
D000475:Alkenes; D001593:Benzyl Compounds; D007097:Imines; D009532:Nickel
chain-walking polymerization; periodically branched; trans-4-octene; α-diimine nickel(II) catalysts