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Volumn 69, Issue 19, 2004, Pages 6173-6184

Proton as the simplest of all catalysts for [2 + 2] cycloadditions: DFT study of acid-catalyzed imine metathesis

Author keywords

[No Author keywords available]

Indexed keywords

ACTIVATION ANALYSIS; BENZENE; ELECTROSTATICS; MATHEMATICAL MODELS; PH EFFECTS; PROBABILITY DENSITY FUNCTION; PROTONS; SOLVENTS; SUBSTITUTION REACTIONS;

EID: 4644299899     PISSN: 00223263     EISSN: None     Source Type: Journal    
DOI: 10.1021/jo049250e     Document Type: Article
Times cited : (13)

References (69)
  • 9
    • 0038390685 scopus 로고
    • Ebdon, J. R., Ed.; Chapman and Hall: New York
    • Amass, A. J. In New Methods of Polymer Synthesis; Ebdon, J. R., Ed.; Chapman and Hall: New York, 1991; p 76.
    • (1991) New Methods of Polymer Synthesis , pp. 76
    • Amass, A.J.1
  • 31
    • 4644364391 scopus 로고
    • Schrödinger, L.L.C.: Portland, OR
    • Jaguar, 5.5 ed.; Schrödinger, L.L.C.: Portland, OR, 1991-2003.
    • (1991) Jaguar, 5.5 Ed.
  • 51
    • 4644282452 scopus 로고    scopus 로고
    • note
    • See Supporting Information for details.
  • 56
    • 4644251782 scopus 로고    scopus 로고
    • note
    • Clearly, van der Waals interactions will play a role in favoring the formation of the precoordination complex. However, DFT methods are well-known to completely neglect these attractive forces. Thus, our energy estimates must be taken as upper limits with the real values probably being 2-3 kcal/mol lower than computed.
  • 57
    • 4644334778 scopus 로고    scopus 로고
    • note
    • Note that we indicate transition states in Figures 1 and 3 that connect the free reactants with the precoordination complexes. These transition states cannot be located reliably using standard transition searches that samply the electronic energy surface, because they are highly dominated by translational entropy changes. A more detailed discussion of this problem can be found, e.g., in ref 65
  • 60
    • 4644316356 scopus 로고    scopus 로고
    • note
    • The electronic structure of 2-TS1 was calculated with the restricted spin formalism. As pointed out by a reviewer, it is possible that our computed configuration is only stable as a result of the restricted formalism. Thus, we have repeated the calculations in the unrestricted spin framework and found our proposed wave function to be stable.
  • 67
    • 4644276530 scopus 로고    scopus 로고
    • note
    • See Computational Details for an overview of the different terms.
  • 68
    • 4644248501 scopus 로고    scopus 로고
    • note
    • The use of B3LYP/6-31G** in geometry optimization also gave activation energies that were ∼4 kcal/mol too low (see Supporting Information). Thus, we contribute ∼5 kcal/mol of the disagreement to the smaller basis set and ∼5 kcal/mol to the use of BLYP instead of B3LYP. Note that the hybrid functional B3LYP requires Hartree-Fock calculations, which are not available in pure DFT packages, such as ADF.
  • 69
    • 4644276531 scopus 로고    scopus 로고
    • note
    • We use the energy unit eV in addition to kcal/mol to avoid nonintuitively large numerical values that would be required for for the Ziegler-Rauk terms.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.