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Volumn 31, Issue 21, 1998, Pages 7149-7165

Termination, isomerization, and propagation reactions during ethene polymerization catalyzed by Cp2Zr-R+ and Cp*2Zr-R+. An experimental and theoretical investigation

Author keywords

[No Author keywords available]

Indexed keywords

ACTIVATION ENERGY; CATALYSTS; ETHYLENE; ISOMERIZATION; MATHEMATICAL MODELS; MOLECULAR STRUCTURE; MOLECULAR WEIGHT DISTRIBUTION; MONOMERS; PRESSURE EFFECTS; REACTION KINETICS; SOLVENTS;

EID: 0032181123     PISSN: 00249297     EISSN: None     Source Type: Journal    
DOI: 10.1021/ma980694k     Document Type: Article
Times cited : (116)

References (57)
  • 35
    • 0022991169 scopus 로고
    • Keii, T., Soga, K. Eds.; Kodansha Elsevier: Tokyo
    • Ewen, J. A. In Studies in Surface Science Catalysis; Keii, T., Soga, K. Eds.; Kodansha Elsevier: Tokyo, 1986; Vol. 25, pp 271-292.
    • (1986) Studies in Surface Science Catalysis , vol.25 , pp. 271-292
    • Ewen, J.A.1
  • 36
    • 0343992800 scopus 로고    scopus 로고
    • Molecular Simulations: San Diego
    • DMol User Guide September 1996; Molecular Simulations: San Diego, 1996.
    • (1996) DMol User Guide September 1996
  • 39
    • 3743056652 scopus 로고    scopus 로고
    • note
    • + we find a reaction energy and zero-point reaction enthalpy of-80 and -57 kJ/mol, respectively, whereas the corresponding numbers for the insertion barrier are 26 and 33 kJ/mol. This agrees well with our expectations and leaves considerable justification for using the calculated activation energies in a discussion of the experiments.
  • 46
    • 3743153585 scopus 로고    scopus 로고
    • note
    • In Figure 7A, we have omitted the data from runs 6 and 22 from the FTIR measurements and run 15 from the GPC measurement because these values clearly deviate more than 3 times the standard deviation of the data.
  • 50
    • 0031380472 scopus 로고    scopus 로고
    • Some attempts to model the influence of MAO on the polymerization have appeared in the literature lately, see, e.g., ref 10 and: Fusco, R.; Longo, L.; Masi, F.; Garbassi, F. Macromolecules 1997, 30, 7673-7685.
    • (1997) Macromolecules , vol.30 , pp. 7673-7685
    • Fusco, R.1    Longo, L.2    Masi, F.3    Garbassi, F.4
  • 52
    • 85088075949 scopus 로고    scopus 로고
    • note
    • -1.
  • 53
    • 3743061167 scopus 로고    scopus 로고
    • note
    • Some of the calculations with L = Cp were performed with a propyl chain, whereas with L = Cp*, we have always started with a butyl chain. With β-agostic structures, we have verified that there are only minor differences between results based on a propyl and a butyl chain. However, in connection with the isomerization reaction, it is necessary to use at least a butyl chain.
  • 54
    • 85088078437 scopus 로고    scopus 로고
    • note
    • β.
  • 55
    • 3743060058 scopus 로고    scopus 로고
    • note
    • Backside insertion into a γ-agostic structure has been attempted but found to be extremely unlikely. The activation energy is more than 170 kJ/mol, even with L = Cp.
  • 56
    • 3743061166 scopus 로고    scopus 로고
    • note
    • An attempt to model termination by transfer of a γ-hydrogen shows that it is highly unlikely. This is as expected, since it would have to be accompanied by additional hydrogen migration.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.