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Volumn 10, Issue 3, 2008, Pages 389-392

Duplexiphane: A polyaromatic receptor containing two adjoined Δ-shaped cavities for an efficient hopping of a single silver cation

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EID: 38949106877     PISSN: 15237060     EISSN: None     Source Type: Journal    
DOI: 10.1021/ol7026762     Document Type: Article
Times cited : (16)

References (28)
  • 17
    • 0028821294 scopus 로고    scopus 로고
    • Compare: Heirtzler, F. R.; Hopf, H.; Jones, P. G.; Bubenitschek, P. Tetrahedron Lett. 1995, 36, 1239.
    • Compare: Heirtzler, F. R.; Hopf, H.; Jones, P. G.; Bubenitschek, P. Tetrahedron Lett. 1995, 36, 1239.
  • 18
    • 38949188569 scopus 로고    scopus 로고
    • The term duplexiphane was coined based on the suggestion by our colleague James R. Kincaid who pointed out that the structure of 3 conceptually resembles that of a duplex, a house partitioned to accom-modate two residents.
    • The term "duplexiphane" was coined based on the suggestion by our colleague James R. Kincaid who pointed out that the structure of 3 conceptually resembles that of a "duplex", a house partitioned to accom-modate two residents.
  • 23
    • 38949107268 scopus 로고    scopus 로고
    • For chemical exchanges, the line shape of the NMR resonances depends on the chemical shift difference between the states involved in the exchange process. In a two-site exchange, coalescence occurs when the exchange rate kex, πΔv/√2, 2.22Δv, where Δv is the chemical shift difference in Hz.11 In this study, Δv is around 100 Hz on a 300 MHz instrument. Thus, the slow intermolecular exchange rate is expected to be in the vicinity of ∼200 s-1 at 22 °C, since we observed only one broad peak for each proton. It should be contrasted that an intermolecular exchange, akin to Scheme 2, with deltaphane (2) was noted4b to be much faster than NMR time scale at 22 °C, i.e. >200 Hz
    • 4b to be much faster than NMR time scale at 22 °C, i.e. >200 Hz.
  • 25
    • 38949168069 scopus 로고    scopus 로고
    • The chemical shifts of me two resonances involved in the fast exchange are unknown. We only observed a weight average of the two states. Therefore, we estimated that on a 300 MHz NMR instrument, based on the chemical shifts of Ag+-bound and unbound 3, the chemical shift difference between these two resonances is roughly 200 Hz. Accordingly, at 22 °C where little chemical exchange was observed, the exchange rate should be at least a couple of orders of magnitude larger than 400 Hz. At -95 °C, the lowest temperature accessible to us, we observed significant line broadening, indicating that the exchange rate at this temperature decreases to ∼400 s-1
    • -1.
  • 26
    • 38949210645 scopus 로고    scopus 로고
    • The synthetic details and X-ray crystallographic structural characterization of the model receptor 9 will be published separately
    • The synthetic details and X-ray crystallographic structural characterization of the model receptor 9 will be published separately.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.