Neodymium dihalide complexes with a tridentate amidinate phosphine oxide ligand: synthesis, structure, and catalytic activity in isoprene polymerization
The deprotonation of amidine 2-[Ph 2 P(O)]C 6 H 4 NHC(Bu t )=N(2,6-Me 2 C 6 H 3 ) ( 1 ) with BunLi affords lithium amidinate {2-[Ph 2 P(O)]C 6 H 4 NLiC(Bu t )=N(2,6-Me 2 C 6 H 3 )}2 ( 2 ) having a dimeric structure, as demonstrated by X-ray diffraction. New amidinate dihalide complexes {2-[Ph 2 P(O)...
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Published in | Russian chemical bulletin Vol. 68; no. 1; pp. 32 - 39 |
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Main Authors | , , , , , |
Format | Journal Article |
Language | English |
Published |
New York
Springer US
01.01.2019
Springer Nature B.V |
Subjects | |
Online Access | Get full text |
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Summary: | The deprotonation of amidine 2-[Ph
2
P(O)]C
6
H
4
NHC(Bu
t
)=N(2,6-Me
2
C
6
H
3
) (
1
) with BunLi affords lithium amidinate {2-[Ph
2
P(O)]C
6
H
4
NLiC(Bu
t
)=N(2,6-Me
2
C
6
H
3
)}2 (
2
) having a dimeric structure, as demonstrated by X-ray diffraction. New amidinate dihalide complexes {2-[Ph
2
P(O)]C
6
H
4
NC(Bu
t
)N(2,6-Me
2
C
6
H
3
)}NdHal
2
(THF)
2
(Hal = I (
3
), Cl (
4
)) were synthesized by exchange reactions of lithium and potassium amidinates with anhydrous neodymium halides NdHal
3
(THF)
n
(Hal = I,
n
= 3.5; Cl,
n
= 0). The X-ray diffraction studies showed that the new compounds are monomeric and the amidinate ligand is tridentate. Chloride complex 4 involved in the three- and four-component catalyst systems 4–AlR
3
–[Ph3C] [B(C
6
F
5
)
4
] (1: 10: 1; AlR
3
= AlBu
i
3, AlMe
3
),
4
–AlR
3
–Pr
i
OH (1: 10: 10; AlR
3
= AlBu
i
3
, AlMe
3
), and 4–AlR
3
–[Ph
3
C][B(C
6
F
5
)
4
]–Pr
i
OH (1: 10: 1: 10; AlR
3
= AlBu
i
3
, AlMe
3
) exhibits activity in stereospecific isoprene polymerization and allows the preparation of high-molecular-weight polyisoprene samples with exceptionally high
cis
-1,4-unit content (up to 99.4%). |
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ISSN: | 1066-5285 1573-9171 |
DOI: | 10.1007/s11172-019-2412-8 |