Highly isoselective coordination polymerization of ortho-methoxystyrene with β-diketiminato rare-earth-metal precursors.
Stereoselective coordination/insertion polymerization of the polar ortho-methoxystyrene has been achieved for the first time by using the cationic β-diketiminato rare-earth-metal species. High activity and excellent isoselectivity (mmmm>99 %) were acheived. The unmasked Lewis-basic methoxy group does not poison the Lewis-acidic metal center, but instead activates the polymerization through σ-π chelation to the active species together with the vinyl group, thus lower the coordination and activation energies as compared with those of styrene derivatives lacking the methoxy group.
State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022 (China).
Dongtao
D
Liu
Changguang
C
Yao
Rong
R
Wang
Meiyan
M
Wang
Zichuan
Z
Wang
Chunji
C
Wu
Fei
F
Lin
Shihui
S
Li
Xinhua
X
Wan
Dongmei
D
Cui
density functional calculations; isoselective polymerization; ortho-methoxystyrene; rare-earth metal complex; β-diketiminate ligand