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Article: Doubly docked pseudorotaxanes

TitleDoubly docked pseudorotaxanes
Authors
KeywordsHost-guest chemistry
Inclusion compounds
Molecular recognition
Pseudorotaxanes
Supramolecular devices
Issue Date1998
Citation
Chemistry - A European Journal, 1998, v. 4, n. 8, p. 1523-1534 How to Cite?
AbstractThe complexation phenomena associated with the ditopic crown ether bis-p-phenylene[34] crown-10 (BPP34C10) and four bisammonium salts, each endowed with two bulky 3,5-di-tert-butylbenzyI termini and a pair of NH2+ centers that are linked through a suitable spacer unit, have been studied. These studies have led to a route to the supramolecular syntheses of singly stranded, doubly docked [2]pseudorotaxanes, in which each NH2+ center interacts simultaneously with the crown ether's independent polyether arcs, so that one dicationic unit can interpenetrate the cavity of one BPP34C10 macroring by means of hydrogen-bonding interactions. NMR spectroscopy, mass spectrometry, and X-ray crystallography demonstrate (in solution, in the gas phase, and in the solid state, respectively) that the doubly docked [2]pseudorotaxanes are generated through the self-assembly of BPP34C10 with bisammonium dications bearing p-xylylene, 2,6-naphthalenebis(methylene), or hexa-methylene spacer units. In contrast, X-ray crystallography shows that a supermolecule, possessing a hot-dog-like co-conformation, is synthesized noncovalently when BPP34C10 self-assembles with a bisammonium salt in which the NH2+ centers are separated by a shorter pentamethylene spacer unit. The double docking of one of the bisammonium dications within BPP34C10's cavity has been utilized in a prototypical chromophoric supramolecular device that operates in response to changes in its surrounding pH. A 1:1:1 solution of the hexafluorophosphate salt of this bisammonium dication with BPP34C10 and a 4,4'-bipyridinium salt is colorless, since the crown ether complexes preferentially with the bisammonium dication. Conversely, it is red in the presence of iPr2NEt because the NH2/+ centers are deprotonated, forcing the crown ether to interact with the 4,4'-bipyridinium salt by means of, inter alia, charge-transfer interactions. This process is reversible, since the solution is decolorized upon treatment with CF3CO2H.
Persistent Identifierhttp://hdl.handle.net/10722/333586
ISSN
2023 Impact Factor: 3.9
2023 SCImago Journal Rankings: 1.058
ISI Accession Number ID

 

DC FieldValueLanguage
dc.contributor.authorAshton, Peter R.-
dc.contributor.authorFyfe, Matthew C.T.-
dc.contributor.authorMartínez-Díaz, M. Victoria-
dc.contributor.authorMenzer, Stephan-
dc.contributor.authorSchiavo, Cesare-
dc.contributor.authorStoddart, J. Fraser-
dc.contributor.authorWhite, Andrew J.P.-
dc.contributor.authorWilliams, David J.-
dc.date.accessioned2023-10-06T05:20:48Z-
dc.date.available2023-10-06T05:20:48Z-
dc.date.issued1998-
dc.identifier.citationChemistry - A European Journal, 1998, v. 4, n. 8, p. 1523-1534-
dc.identifier.issn0947-6539-
dc.identifier.urihttp://hdl.handle.net/10722/333586-
dc.description.abstractThe complexation phenomena associated with the ditopic crown ether bis-p-phenylene[34] crown-10 (BPP34C10) and four bisammonium salts, each endowed with two bulky 3,5-di-tert-butylbenzyI termini and a pair of NH2+ centers that are linked through a suitable spacer unit, have been studied. These studies have led to a route to the supramolecular syntheses of singly stranded, doubly docked [2]pseudorotaxanes, in which each NH2+ center interacts simultaneously with the crown ether's independent polyether arcs, so that one dicationic unit can interpenetrate the cavity of one BPP34C10 macroring by means of hydrogen-bonding interactions. NMR spectroscopy, mass spectrometry, and X-ray crystallography demonstrate (in solution, in the gas phase, and in the solid state, respectively) that the doubly docked [2]pseudorotaxanes are generated through the self-assembly of BPP34C10 with bisammonium dications bearing p-xylylene, 2,6-naphthalenebis(methylene), or hexa-methylene spacer units. In contrast, X-ray crystallography shows that a supermolecule, possessing a hot-dog-like co-conformation, is synthesized noncovalently when BPP34C10 self-assembles with a bisammonium salt in which the NH2+ centers are separated by a shorter pentamethylene spacer unit. The double docking of one of the bisammonium dications within BPP34C10's cavity has been utilized in a prototypical chromophoric supramolecular device that operates in response to changes in its surrounding pH. A 1:1:1 solution of the hexafluorophosphate salt of this bisammonium dication with BPP34C10 and a 4,4'-bipyridinium salt is colorless, since the crown ether complexes preferentially with the bisammonium dication. Conversely, it is red in the presence of iPr2NEt because the NH2/+ centers are deprotonated, forcing the crown ether to interact with the 4,4'-bipyridinium salt by means of, inter alia, charge-transfer interactions. This process is reversible, since the solution is decolorized upon treatment with CF3CO2H.-
dc.languageeng-
dc.relation.ispartofChemistry - A European Journal-
dc.subjectHost-guest chemistry-
dc.subjectInclusion compounds-
dc.subjectMolecular recognition-
dc.subjectPseudorotaxanes-
dc.subjectSupramolecular devices-
dc.titleDoubly docked pseudorotaxanes-
dc.typeArticle-
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1002/(SICI)1521-3765(19980807)4:8<1523::AID-CHEM1523>3.0.CO;2-V-
dc.identifier.scopuseid_2-s2.0-0031829504-
dc.identifier.volume4-
dc.identifier.issue8-
dc.identifier.spage1523-
dc.identifier.epage1534-
dc.identifier.isiWOS:000075389000021-

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