Chain‐walking polymerization of ethylene and 1‐octene with ortho ‐phenyl‐based α ‐diimine Ni (II) catalysts
A class of ortho ‐phenyl‐substituted Ni (II) α ‐diimine complexes with variable electronic nature in the 4‐phenyl position, {[(4‐Me‐2‐(4‐R‐C 6 H 4 )C 6 H 3 N=C) 2 Naphth]NiBr 2 , R = OMe ( C1 ); R = Me ( C2 ); R = H ( C3 )}, was prepared and characterized. These nickel dibromide complexes were confi...
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Veröffentlicht in: | Applied organometallic chemistry 2023-11, Vol.37 (11) |
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Hauptverfasser: | , , , , , , , |
Format: | Artikel |
Sprache: | eng |
Schlagworte: | |
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Zusammenfassung: | A class of
ortho
‐phenyl‐substituted Ni (II)
α
‐diimine complexes with variable electronic nature in the 4‐phenyl position, {[(4‐Me‐2‐(4‐R‐C
6
H
4
)C
6
H
3
N=C)
2
Naphth]NiBr
2
, R = OMe (
C1
); R = Me (
C2
); R = H (
C3
)}, was prepared and characterized. These nickel dibromide complexes were confirmed by X‐ray crystallography analysis and crystallized as a centrosymmetric bromine‐bridged dimer in a distorted tetrahedral geometry at the two Ni (II) centers connected by a four‐membered ring. Because of the conjugation effect and steric hindrance effect of
ortho
‐phenyl substituent, these Ni‐Et
2
AlCl systems via controlled chain‐walking ethylene polymerization performed with high catalytic activities of up to 3.10 × 10
6
g PE (mol Ni h)
−1
to yield high molecular weight branched PEs with narrow
M
w
/
M
n
values (PDI ≤ 2.39). This Ni (II) system also conducted the chain‐walking polymerization of 1‐octene, resulting in highly branched polyolefins (up to 10
7
branches/1000C). |
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ISSN: | 0268-2605 1099-0739 |
DOI: | 10.1002/aoc.7246 |