File Download

There are no files associated with this item.

  Links for fulltext
     (May Require Subscription)
Supplementary

Article: Stereochemistry of molecular figures-of-eight

TitleStereochemistry of molecular figures-of-eight
Authors
Keywordsclick chemistry
donor-acceptor systems
rotaxane
topology
X-ray diffraction
Issue Date2012
Citation
Chemistry - A European Journal, 2012, v. 18, n. 33, p. 10312-10323 How to Cite?
AbstractA trans isomer of a figure-of-eight (Fo8) compound was prepared from an electron-withdrawing cyclobis(paraquat-p-phenylene) derivative carrying trans-disposed azide functions between its two phenylene rings. Copper(I)-catalyzed azide-alkyne cycloadditions with a bispropargyl derivative of a polyether chain, interrupted in its midriff by an electron-donating 1,5-dioxynaphthalene unit acting as the template to organize the reactants prior to the onset of two click reactions, afforded the Fo8 compound with C i symmetry. Exactly the same chemistry is performed on the cis-bisazide of the tetracationic cyclophane to give a Fo8 compound with C 2 symmetry. Both of these Fo8 compounds exist as major and very minor conformational isomers in solution. The major conformation in the trans series, which has been characterized by X-ray crystallography, adopts a geometry which maximizes its C-H⋯O interactions, while maintaining its π⋯π stacking and C-H⋯π interactions. Ab initio calculations at the M06L level support the conformational assignments to the major and minor isomers in the trans series. Dynamic 1H NMR spectroscopy, supported by 2D 1H NMR experiments, indicates that the major and minor isomers in both the cis and trans series equilibrate in solution on the 1H NMR timescale rapidly above and slowly below room temperature. The use of topological concepts and the application of molecular symmetry arguments are crucial when it comes to identifying the structure and dynamics of higher-order topologies, such as those exemplified by molecular figures-of-eight. Using topological concepts, the ability to design and synthesize this particular molecular representation of a mathematical topology has been demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Persistent Identifierhttp://hdl.handle.net/10722/333622
ISSN
2023 Impact Factor: 3.9
2023 SCImago Journal Rankings: 1.058
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorBoyle, Megan M.-
dc.contributor.authorGassensmith, Jeremiah J.-
dc.contributor.authorWhalley, Adam C.-
dc.contributor.authorForgan, Ross S.-
dc.contributor.authorSmaldone, Ronald A.-
dc.contributor.authorHartlieb, Karel J.-
dc.contributor.authorBlackburn, Anthea K.-
dc.contributor.authorSauvage, Jean Pierre-
dc.contributor.authorStoddart, J. Fraser-
dc.date.accessioned2023-10-06T05:21:06Z-
dc.date.available2023-10-06T05:21:06Z-
dc.date.issued2012-
dc.identifier.citationChemistry - A European Journal, 2012, v. 18, n. 33, p. 10312-10323-
dc.identifier.issn0947-6539-
dc.identifier.urihttp://hdl.handle.net/10722/333622-
dc.description.abstractA trans isomer of a figure-of-eight (Fo8) compound was prepared from an electron-withdrawing cyclobis(paraquat-p-phenylene) derivative carrying trans-disposed azide functions between its two phenylene rings. Copper(I)-catalyzed azide-alkyne cycloadditions with a bispropargyl derivative of a polyether chain, interrupted in its midriff by an electron-donating 1,5-dioxynaphthalene unit acting as the template to organize the reactants prior to the onset of two click reactions, afforded the Fo8 compound with C i symmetry. Exactly the same chemistry is performed on the cis-bisazide of the tetracationic cyclophane to give a Fo8 compound with C 2 symmetry. Both of these Fo8 compounds exist as major and very minor conformational isomers in solution. The major conformation in the trans series, which has been characterized by X-ray crystallography, adopts a geometry which maximizes its C-H⋯O interactions, while maintaining its π⋯π stacking and C-H⋯π interactions. Ab initio calculations at the M06L level support the conformational assignments to the major and minor isomers in the trans series. Dynamic 1H NMR spectroscopy, supported by 2D 1H NMR experiments, indicates that the major and minor isomers in both the cis and trans series equilibrate in solution on the 1H NMR timescale rapidly above and slowly below room temperature. The use of topological concepts and the application of molecular symmetry arguments are crucial when it comes to identifying the structure and dynamics of higher-order topologies, such as those exemplified by molecular figures-of-eight. Using topological concepts, the ability to design and synthesize this particular molecular representation of a mathematical topology has been demonstrated. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.-
dc.languageeng-
dc.relation.ispartofChemistry - A European Journal-
dc.subjectclick chemistry-
dc.subjectdonor-acceptor systems-
dc.subjectrotaxane-
dc.subjecttopology-
dc.subjectX-ray diffraction-
dc.titleStereochemistry of molecular figures-of-eight-
dc.typeArticle-
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1002/chem.201202070-
dc.identifier.scopuseid_2-s2.0-84864599212-
dc.identifier.volume18-
dc.identifier.issue33-
dc.identifier.spage10312-
dc.identifier.epage10323-
dc.identifier.eissn1521-3765-
dc.identifier.isiWOS:000307108100023-

Export via OAI-PMH Interface in XML Formats


OR


Export to Other Non-XML Formats