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Volumn 124, Issue 43, 2002, Pages 12796-12805

Theoretical study of anion binding to calix[4]pyrrole: The effects of solvent, fluorine substitution, cosolute, and water traces

Author keywords

[No Author keywords available]

Indexed keywords

FREE ENERGY; HYDRATION; INTEGRATION; MOLECULAR DYNAMICS; SUBSTITUTION REACTIONS;

EID: 0037202186     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja020318m     Document Type: Article
Times cited : (69)

References (54)
  • 41
    • 84926229748 scopus 로고    scopus 로고
    • note
    • - (2.32, 0.09). The radii used here are ∼0.2-0.3 Å shorter than those typically used to simulate halogens in aqueous solution (like the OPLS parameters). Energy calculations using standard OPLS parameters lead to a sizable underestimation of pyrrol-halogen interaction and to an overestimation of the halogen-pyrrol distance. Thus, classical calculations using the OPLS force field for halogens lead to a systematic underestimation of ∼4-6 kcal/mol in the stabilization energy of the halogen-pyrrol (or 3,4-difluoropyrrole) complex and to an overestimation of ∼0.3 Å of the equilibrium distance. Since the deviation between QM and OPLS values is similar for all halogens, the change of van der Waals radii does not have an impact in the relative free energy of binding of halogens but can be important for the description of the preferential binding of halogens relative to other ions such as the phosphate, which are described with van der Waals parameters which lead to an accurate description of the ion-pyrrole interaction (0.5 (pyrrole) and 0.9 (3,4-difiuoropyrrole) kcal/mol difference between classical and QM calculations).
  • 42
    • 0001039044 scopus 로고
    • Different authors have suggested that phosphate exists mostly as a dimer in solution (Chu, F.; Flatt, L. S.; Anslyn, E. V. J. Am. Chem. Soc. 1994, 116, 4194), but this implies the existence of a monoanionic complex, with one phosphate and one phosphoric acid. The protonation of the phosphate anion is not likely to occur in the aprotic systems simulated here, and molecular dynamics simulations have shown that the phosphate- phosphate dimer is unstable in all the solvents studied here. Accordingly, the unbound form of the phosphate considered here is that corresponding to the isolated anionic compound.
    • (1994) J. Am. Chem. Soc. , vol.116 , pp. 4194
    • Chu, F.1    Flatt, L.S.2    Anslyn, E.V.3
  • 50
  • 53
    • 84926230517 scopus 로고    scopus 로고
    • note
    • - are subjected to non-negligible statistical errors related to the dissociation of the ion pair along the mutation. Accordingly, all the free energy calculations reported in this part of the work should be taken with caution, since they might not be as accurate as simulations in pure solvents.
  • 54
    • 84926230617 scopus 로고    scopus 로고
    • Unpublished results
    • Sessler, J. Unpublished results.
    • Sessler, J.1


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.