Water-soluble pentasulfonatocalix[5]arene: selective recognition of ditopic trimethylammonium cations by a triple non-covalent interaction

Arena, Giuseppe; Gentile, Salvatore; Gulino, Fabio Giuseppe; Sciotto, Domenico; Sgarlata, Carmelo

doi:10.1016/j.tetlet.2004.07.108

Cited by 82 publications

(56 citation statements)

References 15 publications

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“…In all cases the signals of guest protons are observed as averaged single resonances because of the fast exchange on the NMR timescale between the free and complexed guest. [16] As can be seen in Table 1, the δ values of guest protons shift appreciably to higher fields after complexation with calix [4]arenes as compared with the uncomplexed guest. This indicates that the guest molecule is encapsulated into the calixarene cavity to form the intermolecular complex, which thus leads to an efficient shield toward guest protons.…”

Section: Binding Modementioning

confidence: 87%

Molecular Selective Binding of Pyridinium Guest Ions by Water‐Soluble Calix[4]arenes

et al. 2005

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The complex stability constants (KS) and thermodynamic parameters (ΔG°, ΔH°, and TΔS°) for 1:1 intermolecular complexation of water‐soluble calix[4]arene tetrasulfonate (CAS) and thiacalix[4]arene tetrasulfonate (TCAS) with pyridinium guest ions 1–10 have been determined by means of titration calorimetry in an acidic buffer solution (pH = 2.0) at 298.15 K, and their binding modes have been investigated by NMR spectroscopy. Possessing a smaller cavity and a higher π electron density than TCAS, CAS affords the stronger binding abilities for all guests examined, giving an exciting molecular selectivity of up to 354 for the 2,6‐dimethylpyridine/2,6‐pyridinedicarboxylic acid pair. The high binding affinities, attributed to the favorable enthalpic gains, are comprehensively discussed from the viewpoint of π–π stacking, electronic effect and size‐fit relationship between host and guest. The thermodynamic parameters that have been obtained, together with the NMR results, jointly demonstrate that the position, number, and type of substituent groups introduced onto the guest molecule are the key factors controlling the structural‐energetics correlation for the molecular selective binding of water‐soluble calixarenes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)

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Section: Binding Modementioning

confidence: 87%

Molecular Selective Binding of Pyridinium Guest Ions by Water‐Soluble Calix[4]arenes

et al. 2005

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“…Moreover, the upper-rim sulfonate groups provide additional anchoring points, which enable SCnA to display especially strong binding ability and high molecular selectivity towards a variety of organic ions. [11][12][13][14] Although the SCnA homologues have been extensively studied, [4,[15][16][17][18] their binding behavior as a function of lower-rim modification has only been addressed to a small extent. For example, Arena and co-workers reported that lower-rim modification of SC4A with carboxylate groups provides specific preorganization of the host cavity, which affects its selectivity towards organic ammonium plexation.…”

Section: Introductionmentioning

confidence: 99%

Effect of Lower‐Rim Alkylation of p‐Sulfonatocalix[4]arene on the Thermodynamics of Host–Guest Complexation

et al. 2010

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The complex stability constants (KS) and thermodynamic parameters (ΔH° and TΔS°) for the 1:1 complexation of two water‐soluble calixarenes, p‐sulfonatocalix[4]arene (SC4A) and 5,11,17,23‐tetrasulfonato‐25,26,27,28‐tetrakis(n‐butyl)calix[4]arene (SC4A‐Bu), with organic ammonium cations and neutral spherical organic molecules, have been determined by means of isothermal titration calorimetry (ITC) in aqueous solutions at 298.15 K. The obtained results indicate that, upon complexation with these guests by SC4A‐Bu, the enthalpy changes become less favorable, whereas the entropy changes become more favorable relative to SC4A complexation. These differences can be attributed to differential degrees of desolvation and removal of high‐energy water as well as the change in conformation or conformational degrees of freedom upon complexation. The calorimetric investigations, accompanied by 1H NMR and UV/Vis spectroscopy and X‐ray crystallography provide a thermodynamic explanation for the different complexation behavior of SC4A and SC4A‐Bu towards charged and neutral organic guests. Binding ability and molecular selectivity are discussed from the viewpoint of the conformational geometry and electronic properties of hosts and guests.

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“…[103] Bei Benzolderivaten können sich entweder die Aryleinheit oder die Substituenten im Hohlraum befinden. [105,109,110] Wegen ihrer hohen Wasserlöslichkeit wurden Salze der sulfonierten Calix [4] [109] in Wasser derart, dass ausschließlich die Alkylammoniumgruppe in den Hohlraum aufgenommen wird. Calix [6]arenhexasulfonat 50 (n = 6,…”

Section: Cyclophane Mit Mehreren (Hetero-)areneinheiten Und Unterschiunclassified

Supramolekulare Chemie in Wasser

2007

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Die supramolekulare Chemie in Wasser ist ein ständig wachsendes Forschungsgebiet, da nichtkovalente Wechselwirkungen in wässrigen Medien entscheidend für ein besseres Verständnis und die Kontrolle grundlegender Prozesse in der Natur sind. Dieser Aufsatz bietet einen Überblick über aktuelle Entwicklungen auf den Gebieten der wasserlöslichen synthetischen Rezeptoren, der Selbstorganisation und der molekularen Erkennung in Wasser unter Berücksichtigung von Funktionalitäten, die zur Verbesserung der Wasserlöslichkeit eingeführt werden, sowie der supramolekularen Wechselwirkungen und der Methoden, die für eine effiziente Gasterkennung und Selbstorganisation in Wasser eingesetzt werden. Zudem beschreibt er die besonderen Eigenschaften und Anwendungsmöglichkeiten supramolekularer Einheiten in wässrigen Medien.

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Water-soluble pentasulfonatocalix[5]arene: selective recognition of ditopic trimethylammonium cations by a triple non-covalent interaction

Cited by 82 publications

References 15 publications

Molecular Selective Binding of Pyridinium Guest Ions by Water‐Soluble Calix[4]arenes

Molecular Selective Binding of Pyridinium Guest Ions by Water‐Soluble Calix[4]arenes

Effect of Lower‐Rim Alkylation of p‐Sulfonatocalix[4]arene on the Thermodynamics of Host–Guest Complexation

Supramolekulare Chemie in Wasser

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