메뉴 건너뛰기




Volumn 24, Issue 9, 2005, Pages 2129-2140

Theoretical study of Cp2Zr-, (MeO)2Zr-, and M(PH 3)-Mediated coupling reactions of acetylenes (M = Ni, Pt). Significant differences between early-and late-transition-metal complexes

Author keywords

[No Author keywords available]

Indexed keywords

ACETYLENE; ACTIVATION ENERGY; CHEMICAL BONDS; COMPLEXATION; PROBABILITY DENSITY FUNCTION; STEREOCHEMISTRY;

EID: 18444383955     PISSN: 02767333     EISSN: None     Source Type: Journal    
DOI: 10.1021/om050128v     Document Type: Article
Times cited : (18)

References (112)
  • 72
    • 18444384637 scopus 로고    scopus 로고
    • note
    • 3) (see Table S1 in the Supporting Information).
  • 73
    • 18444379792 scopus 로고    scopus 로고
    • note
    • 3) is considered a reasonable model.
  • 75
    • 18444406403 scopus 로고    scopus 로고
    • note
    • 2 as a substrate because our main purpose is to make clear comparisons in the reaction behavior and reactivity between early- and late-transition-metal complexes. It is likely that the bulky substituents increase the activation barrier of both early- and late-transition-metal-mediated coupling reactions.
  • 93
    • 18444392839 scopus 로고    scopus 로고
    • note
    • 2 becomes less stable in energy by 18.4 kcal/mol (DFT/BS-II calculation) relative to the precursor complex, when the C atom of the third acetylene approaches the Zr center at 2.5 A (see Figure S5 in the Supporting Information). The transition state could not be optimized at this moment, but it should be less stable than this geometry.
  • 94
    • 18444398167 scopus 로고    scopus 로고
    • note
    • 2Zr, probably because the coupling product contains a very strained cyclobutene ring.
  • 96
    • 18444387524 scopus 로고    scopus 로고
    • note
    • 4-5.
  • 97
    • 84942791030 scopus 로고
    • Wilkinson, G., Stone, F. G. A., Eds.; Pergamon: Oxford, U.K.
    • Hartley, F. R. In Comprehensive Organometallic Chemistry; Wilkinson, G., Stone, F. G. A., Eds.; Pergamon: Oxford, U.K., 1982; Vol. 6, p 471.
    • (1982) Comprehensive Organometallic Chemistry , vol.6 , pp. 471
    • Hartley, F.R.1
  • 103
    • 18444395077 scopus 로고    scopus 로고
    • note
    • 3 interacts with the π* orbital of acetylene in 9.
  • 104
    • 18444403863 scopus 로고    scopus 로고
    • note
    • This value of 0.3 means that the reaction proceeds by 30% from the transition state to the product.
  • 105
    • 18444366022 scopus 로고    scopus 로고
    • note
    • 3)-mediated coupling reaction (see Figure 3). As a result, the energy change is not smoothly presented in Figure 4.
  • 107
    • 18444398479 scopus 로고    scopus 로고
    • note
    • 3 takes the best position for the π-back-donation interaction with two acetylene molecules in 7 and 10.
  • 108
    • 18444417538 scopus 로고    scopus 로고
    • note
    • 18,19
  • 111
    • 18444381289 scopus 로고    scopus 로고
    • note
    • 2).
  • 112
    • 18444366888 scopus 로고    scopus 로고
    • note
    • The MeO ligand changes its orientation upon going from the reactant to the transition state and the product, as shown in Figure 1. It is likely that the MeO group easily rotates around the Zr-O bond.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.