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Volumn 128, Issue 4, 2006, Pages 1324-1333

Guest exchange dynamics in an M4L6 tetrahedral host

Author keywords

[No Author keywords available]

Indexed keywords

CHEMICAL REACTIONS; KINETIC ENERGY; MOLECULAR VIBRATIONS; PARAMETER ESTIMATION; PORTALS; REACTION KINETICS;

EID: 31944434271     PISSN: 00027863     EISSN: None     Source Type: Journal    
DOI: 10.1021/ja056556+     Document Type: Article
Times cited : (112)

References (87)
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    • Crant, D. J. Nature 1992, 356, 29-36.
    • (1992) Nature , vol.356 , pp. 29-36
    • Crant, D.J.1
  • 57
    • 4544282884 scopus 로고    scopus 로고
    • 5.04; Fujitsu Limited
    • CAChe Workstation Pro, 5.04; Fujitsu Limited: 2002.
    • (2002) CAChe Workstation Pro
  • 58
    • 31944440185 scopus 로고    scopus 로고
    • Parac, T. N.; Raymond, K. N. Unpublished results
    • Parac, T. N.; Raymond, K. N. Unpublished results.
  • 59
    • 31944447538 scopus 로고    scopus 로고
    • Michels, M.; Raymond, K. N. Unpublished results
    • Michels, M.; Raymond, K. N. Unpublished results.
  • 60
    • 31944447945 scopus 로고    scopus 로고
    • note
    • The "empty" host intermediate likely contains solvent (here water), although we have not been able to test this experimentally. As emphasized by a reviewer, the energetic penalties for complete desolvation of the host interior are probably quite large, and it is more plausible that the intermediate host is solvent filled. Throughout the manuscript, "empty" refers to the absence of the described guests and not the absence of solvent; we are not able to comment at this time on the role of encapsulated solvent in the guest exchange process. A distinct role of solvent in the guest exchange dynamics of hydrogen-bonded capsules has been demonstrated in another host-guest system: ref 13.
  • 65
    • 31944436098 scopus 로고    scopus 로고
    • note
    • +. The difference in treatment does not affect the determination of ΔH‡ and ΔV‡.
  • 68
    • 31944431748 scopus 로고    scopus 로고
    • note
    • It is likely that some rearrangement of the exterior ion-paired guests occurs as the host aperture dilates for guest exchange, and this process may contribute to the negative entropy of activation observed for the self-exchange reactions. For systems in which the bimolecular reaction with the G2 guest is rate limiting, the conformational rearrangement of the G2 guest required for it to pass through the host aperture will also contribute to the negative activation entropy.
  • 69
    • 31944444937 scopus 로고    scopus 로고
    • note
    • + due to the temperature limitations of the variable pressure NMR probe.
  • 70
    • 31944450486 scopus 로고    scopus 로고
    • note
    • A positive volume of activation would also be expected for the bond-rupture mechanism, in which one ligand partially dissociates to open up a large host portal for guest egress. The volumes of activation for this mechanism, however, should be independent of guest size.
  • 78
    • 31944441894 scopus 로고    scopus 로고
    • note
    • + exchange, produces similar kinetic behavior (Supporting Information).
  • 79
    • 31944452407 scopus 로고    scopus 로고
    • note
    • 12- host.
  • 82
    • 31944448063 scopus 로고    scopus 로고
    • note
    • Other ion pairing effects can be envisioned. For example, alkali cations are often found ion paired to the negatively charged catecholate caps of ML3 complexes. Large ammonium (or phosphonium) cation concentrations might interfere with this interaction thereby impacting the host dynamics. Additionally, interaction of the ammonium cations with the catecholate cap may itself be a critical parameter to host dynamics.
  • 83
    • 31944438706 scopus 로고    scopus 로고
    • Leung, D. H.; Bergman, R. G.; Raymond, K. N. Unpublished results
    • Leung, D. H.; Bergman, R. G.; Raymond, K. N. Unpublished results.
  • 84
    • 31944442331 scopus 로고    scopus 로고
    • Fiedler, D.; van Halbeek, H.; Bergman, R. G.; Raymond, K. N. Unpublished results
    • Fiedler, D.; van Halbeek, H.; Bergman, R. G.; Raymond, K. N. Unpublished results.
  • 85
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    • note
    • +.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.