1 Ocak 2019 Dergi makalesi Açık Erişim

Pavlovic, Radoslav Z.; Lei Zhiquan; Guney, Murat; Lalisse, Remy F.; Hopf, Ryan G.; Gallucci, Judith; Moore, Curtis; Xie, Han; Hadad, Christopher M.; Badjic, Jovica D.

Dublin Core

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  <dc:creator>Pavlovic, Radoslav Z.</dc:creator>
  <dc:creator>Lei Zhiquan</dc:creator>
  <dc:creator>Guney, Murat</dc:creator>
  <dc:creator>Lalisse, Remy F.</dc:creator>
  <dc:creator>Hopf, Ryan G.</dc:creator>
  <dc:creator>Gallucci, Judith</dc:creator>
  <dc:creator>Moore, Curtis</dc:creator>
  <dc:creator>Xie, Han</dc:creator>
  <dc:creator>Hadad, Christopher M.</dc:creator>
  <dc:creator>Badjic, Jovica D.</dc:creator>
  <dc:date>2019-01-01</dc:date>
  <dc:description>In this work, we report a mechanism by which stereoisomeric and twisted capsules P/M-1 direct their dynamic chirality in the presence of haloalkane guests. The capsule comprises a static, but twisted, cage that is linked to a dynamic tris(2-pyridylmethyl)amine (TPA) lid at its top. From the results of experimental (NMR spectroscopy and X-ray crystallography) and computational (DFT) studies, the TPA lid was shown to assume clockwise (+) and counterclockwise (-) folds with diastereomeric (but racemic) capsules M-1(+) and M-1(-) interconverting at a rapid rate (Delta G(189K)(not equal)=9.1 kcal mol(-1)). The relative stability of the capsules was found to be a function of guest(s) residing in their interior (243/262 angstrom(3)) with small CH2Cl2 (61 angstrom(3)) yielding roughly equal population of diastereomeric inclusion complexes. Larger guests, such as CCl4 (89 angstrom(3)) and CBr4 (108 angstrom(3)), however, formed M-1(-)subset of CX4 at the expense of M-1(+)subset of CX4 in circa 3:1 ratio. To account for the observation, theory (DFT:M06-2X/6-31+G*) and experiments (H-1 NMR spectroscopy) were used to deduce that CX4 guests become localized inside the twisted cage of the capsule by forming a C-X...pi halogen bond [N-c=d/(r(H)+r(X))=0.91-0.92] with the benzene "floor" while encountering electrostatic repulsions with closer naphthalimide boundaries. At last, the TPA lid used its central methylene hydrogens to establish, within the M-1(-)subset of CX4, three stabilizing C-H...X-C interactions with the guest. The same C-H...X-C interactions, however, became weaker (or possibly vanished) after the conformational reorganization of the lid and the formation of less stable M-1(+)subset of CX4 complex. On individual basis, C-H...X-C intermolecular contacts are weak and hardly detectable in the solution phase. In the case of capsule P/M-1, however, these contacts were multivalent and altogether strong enough to direct the host's dynamic chirality.</dc:description>
  <dc:identifier>https://aperta.ulakbim.gov.trrecord/72453</dc:identifier>
  <dc:identifier>oai:zenodo.org:72453</dc:identifier>
  <dc:rights>info:eu-repo/semantics/openAccess</dc:rights>
  <dc:rights>http://www.opendefinition.org/licenses/cc-by</dc:rights>
  <dc:source>CHEMISTRY-A EUROPEAN JOURNAL 25(57) 13124-13130</dc:source>
  <dc:title>Multivalent C-H...Cl/Br-C Interactions Directing the Resolution of Dynamic and Twisted Capsules</dc:title>
  <dc:type>info:eu-repo/semantics/article</dc:type>
  <dc:type>publication-article</dc:type>
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