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Volumn 130, Issue 31, 2008, Pages 10354-10368

Intra- and intermolecular NMR studies on the activation of arylcyclometallated hafnium pyridyl-amido olefin polymerization precatalysts

Author keywords

[No Author keywords available]

Indexed keywords

CATALYSTS; CHEMICAL REACTIONS; HAFNIUM; MONOMERS; NUCLEAR MAGNETIC RESONANCE; OLEFINS; POLYMERIZATION; POLYMERS;

EID: 48749112429     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja802072n     Document Type: Article
Times cited : (102)

References (62)
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    • 0 metals (values of 3-6 ppm indicate coordination; <3 ppm indicates non-coordination). See : Horton, A. D.; de With, J. Organometallics 1997, 16, 5424, and references therein.
    • 0 metals (values of 3-6 ppm indicate coordination; <3 ppm indicates non-coordination). See : Horton, A. D.; de With, J. Organometallics 1997, 16, 5424, and references therein.
  • 31
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    • This value does not take into account the entropic effect. In fact, for the structure 3a we found two stable species with the same energy which differs for the relative configuration of the B(C6F5) 3 moiety. This is not true for 3a′
    • 3 moiety. This is not true for 3a′.
  • 32
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    • 5-transfer to the metal see:(a) Phomphrai, K.; Fenwick, A. E.; Sharma, S.; Fanwick, P. E.; Caruthers, J. M.; Delgass, W. N.; Abu-Omar, M. M.; Rothwell, J. P. Organometallics 2006, 25, 214.
    • 5-transfer to the metal see:(a) Phomphrai, K.; Fenwick, A. E.; Sharma, S.; Fanwick, P. E.; Caruthers, J. M.; Delgass, W. N.; Abu-Omar, M. M.; Rothwell, J. P. Organometallics 2006, 25, 214.
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    • 4043095478 scopus 로고    scopus 로고
    • and references therein. For a recent theroretical work see: g
    • For a recent theroretical work see: (g) Wondimagegn, T.; Xu, Z.; Vanka, K.; Ziegler, T. Organometallics 2004, 23, 3847, and references therein.
    • (2004) Organometallics , vol.23 , pp. 3847
    • Wondimagegn, T.1    Xu, Z.2    Vanka, K.3    Ziegler, T.4
  • 40
    • 85169252711 scopus 로고    scopus 로고
    • Although structures of the hafnium-containing decomposition products were difficult to assign, the appearance of high frequency resonances in the 19F NMR spectrum (around-120 ppm) suggests the formation of Hf-C 6F5 fragments, Tonzetich, Z. J, Schrock, R. R. Polyhedron 2006, 25, 469
    • 5 fragments : Tonzetich, Z. J.; Schrock, R. R. Polyhedron 2006, 25, 469.
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    • 3] ion pair (see Supporting Information).
    • 3] ion pair (see Supporting Information).
  • 43
    • 0035823885 scopus 로고    scopus 로고
    • H34/H8 = 0.35. The distance between H7 and H8, 2.47 Å, Zuccaccia, C.; Bellachioma, G.; Cardaci, G.; Macchioni, A. J. Am. Chem. Soc. 2001, 123, 11020, was used as reference distance, affording 2.44 and 2.94 Å for H34/H17 and H34/H8 distances, respectively.
    • H34/H8 = 0.35. The distance between H7 and H8, 2.47 Å, (Zuccaccia, C.; Bellachioma, G.; Cardaci, G.; Macchioni, A. J. Am. Chem. Soc. 2001, 123, 11020, was used as reference distance, affording 2.44 and 2.94 Å for H34/H17 and H34/H8 distances, respectively.
  • 48
    • 48749133070 scopus 로고    scopus 로고
    • The 1H NMR spectrum allows us to individuate some resonances of MeB(C6F5)2 and Me2B(C 6F5, dH, 0.96 and 1.33 ppm, respectively, while the appearance of high frequency (around-120 ppm) resonances in the 19F NMR spectrum suggests the formation of Hf-C6F5 fragments
    • 5 fragments.
  • 49
    • 48749101262 scopus 로고    scopus 로고
    • The decomposition product could not be completely characterized; 1H NMR data are consistent with formation of a mixed-methyl-chloride hafnium species having a structure similar to 5a, together with [ClCD2NMe2Ph][B(C6F5)4, 1H NMR for the Hf species (CD2Cl2, 298 K, J values in Hz, d 8.71 (d, 3JHH, 8.4, H5, 8.67 (td, 3JHH, 7.4, 4J HH, 1.1, H7, 8.58 (d, 3JHH, 8.4, H3, 8.42 (t, 3JHH, 8.0, H13, 8.33 (dd, 3JHH, 8.4, 4JHH, 7.3, H2, 8.21 (dd, 3JHH, 7.3, 4JHH, 1.1, H1, 8.14 (d, 3J HH, 8.0, H12, 8.12 td, 3JHH, 7.3, 4JHH, 1
    • 2, 298 K): 7.72 (m, 3 protons), 7.42 (m, 2 protons), 3.48 (s, 6 protons).
  • 50
    • 20344403071 scopus 로고    scopus 로고
    • For examples of amine activation, see: (a) Krut'ko, D. P, Borzov, M. V, Kirsanov, R. S, Churakov, A. V, Kuz'mina, L. G. J. Organomet. Chem. 2005, 690, 3243
    • For examples of amine activation, see: (a) Krut'ko, D. P.; Borzov, M. V.; Kirsanov, R. S.; Churakov, A. V.; Kuz'mina, L. G. J. Organomet. Chem. 2005, 690, 3243.
  • 52
    • 0037433240 scopus 로고    scopus 로고
    • For examples of N,N-bis-alkyl-aniline ortho-metallation see: (a) Solé, D, Vallverdù, L, Solans, X, Font-Bardìa, M, Bonjock, J. J. Am. Chem. Soc. 2003, 125, 1587
    • For examples of N,N-bis-alkyl-aniline ortho-metallation see: (a) Solé, D.; Vallverdù, L.; Solans, X.; Font-Bardìa, M.; Bonjock, J. J. Am. Chem. Soc. 2003, 125, 1587.
  • 56
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    • m-H′, p-H and o-H interact with H35.
    • m-H′, p-H and o-H interact with H35.
  • 57
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    • For similar isopropyl C-H activation reactions, see for example
    • (a) For similar isopropyl C-H activation reactions, see for example: Otten, E.; Dijkstra, P.; Visser, C.; Meetsma, A.; Hessen, B. Organometallics 2005, 24, 4374.
    • (2005) Organometallics , vol.24 , pp. 4374
    • Otten, E.1    Dijkstra, P.2    Visser, C.3    Meetsma, A.4    Hessen, B.5
  • 60
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    • Reactions of 8b and 12 with molecular hydrogen at room temperature did not afford any reaction after several hours.
    • Reactions of 8b and 12 with molecular hydrogen at room temperature did not afford any reaction after several hours.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.