Activation of an α-Diimine Ni(II) Precatalyst with AlMe3 and AliBu3: Catalytic and NMR and EPR Spectroscopy Studies
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Original
|
| Journal |
Organometallics
ISSN: 0276-7333
, E-ISSN: 1520-6041
|
| Output data |
Year: 2020,
Volume: 39,
Number: 16,
Pages: 3034-3040
Pages count
: 7
DOI:
10.1021/acs.organomet.0c00395
|
| Tags |
ETHYLENE POLYMERIZATION BEHAVIOR; NICKEL-COMPLEXES; PALLADIUM; COPOLYMERIZATION |
| Authors |
Soshnikov Igor E.
1,2
,
Semikolenova Nina V.
1
,
Bryliakov Konstantin P.
1,2
,
Antonov Artem A.
1,2
,
Sun Wen-Hua
3
,
Talsi Evgenii P.
1,2
|
| Affiliations |
| 1 |
Boreskov Institute of Catalysis, Pr. Lavrentieva, 5, 630090 Novosibirsk, Russian Federation
|
| 2 |
Novosibirsk State University Pirogova 1, 630090 Novosibirsk, Russian Federation
|
| 3 |
State Key Laboratory of Engineering Plastics and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, People’s Republic of China
|
|
Funding (4)
|
1
|
Federal Agency for Scientific Organizations
|
0303-2016-0009
|
|
2
|
Russian Foundation for Basic Research
|
18-53-80031
|
|
3
|
National Natural Science Foundation of China
|
51861145303
|
|
4
|
Chinese Academy of Sciences
|
2020VMA0028
|
The nature of Ni(II) and Ni(I) species formed upon the activation of the N,N-α-diimine Ni(II) precatalyst LNiIIBr2 (1) with AlMe3, MMAO, and AliBu3 has been studied by NMR and EPR spectroscopy (L = 1,4-bis(2,4,6-trimethylphenyl)-2,3-dimethyl-1,4-diazabuta-1,3-diene). It has been shown that the paramagnetic complex 3AlMe3 with the proposed structure [LNiI(μ-Me)2AlMe2] or [(L•–)NiII(μ-Me)2AlMe2] predominates in the reaction solution of 1/AlMe3 at Al/Ni > 10. Upon activation of 1 with MMAO (Al/Ni > 20–30), nickel predominantly exists in the form of the structurally similar complex 3MMAO ([LNiI(μ-Me)2AliBu2] or [(L•–)NiII(μ-Me)2AliBu2]). The reaction of 1 with AliBu3 leads to rapid ligand scrambling, affording the EPR-active complex 4 ([(L•–)AliBu2]). The latter process is accompanied by Ni reduction to the zerovalent state. Possible roles of the observed species in the catalytic systems are discussed.