Induced‐Fit Encapsulation by a 1,3,5‐Alternate Calix[6]arene

Ménand, Mickaël; Leroy, Axel; Marrot, Jérôme; Luhmer, Michel; Jabin, Ivan

doi:10.1002/ange.200901722

Cited by 6 publications

(1 citation statement)

References 29 publications

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“…We recently demonstrated37–41 that the use of the heteroditopic nonsymmetric tris(phenylureido)calix[6]arene derivative 1 (Scheme ) as a three‐dimensional macrocyclic component42 for obtaining oriented pseudorotaxanes and rotaxanes brings about a significant increase in structural complexity because, in principle, it is possible to selectively address the threading of suitable axles from its “upper” or “lower” rim leading to “up” and “down” oriented isomers (Figure 2). In fact, we showed that in apolar media (e.g., benzene) compound 1 is able to act as a very efficient38 wheel that can be threaded exclusively from the upper rim by axles derived from 4,4′‐bipyridinium salts to yield oriented pseudorotaxanes 37.…”

Section: Introductionmentioning

confidence: 99%

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

Arduini

Bussolati

Credi

et al. 2012

Chemistry A European J

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The development of a pseudorotaxane motif capable of performing unidirectional threading and dethreading processes under control of external stimuli is particularly important for the construction of processive linear motors based on rotaxanes and, at least in principle, it discloses the possibility to access to rotary motors based on catenanes. Here, we report a strategy to obtain the solvent-controlled unidirectional transit of a molecular axle through a molecular wheel. It is based on the use of appropriately designed molecular components, the essential feature of which is their non-symmetric structure. Specifically they are an axle containing a central electron-acceptor 4,4'-bipyridinium core functionalized with a hexanol chain at one side, and a stilbene unit connected through a C6 chain at the other side, and a heteroditopic tris(phenylureido)-calix[6]arene wheel. In apolar solvents the axle threads into the wheel from its upper rim and with the end carrying the OH group, giving an oriented pseudorotaxane structure. After a stoppering reaction, which replaces the small hydroxy group with a bulky diphenylacetyl moiety, and replacement of the apolar solvent with a polar one, dethreading occurs through the slippage of the stilbene unit from the lower rim of the wheel, that is, in the same direction of the threading process. The essential role played by the stilbene unit to achieve the unidirectional transit of the axle through the wheel, and to tune the dethreading rate by light is also demonstrated.

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Section: Introductionmentioning

confidence: 99%

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

Arduini

Bussolati

Credi

et al. 2012

Chemistry A European J

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A Biomimetic Heteroditopic Receptor for Zwitterions in Protic Media

Cornut

Moerkerke

Bruylants

et al. 2014

Chemistry An Asian Journal

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The efficient synthesis of calix[6]cryptothiourea 6 was achieved through a two-step sequence that involves a key [1+1] macrocyclization step. It was shown by NMR spectroscopy that this heteroditopic receptor can bind zwitterions in protic media with an outstanding selectivity for β-alanine betaine G5, which is likely due to a high complementarity between the two partners. This result constitutes a rare example of cavity complexation of a zwitterion by a calix[6]arene. In comparison with the parent urea-based receptors, 6 behaves as a much more efficient host for betaines. This strengthening of the binding properties is due to the better preorganization of the tripodal hydrogen-bonding cap as well as to the higher acidity of the thiourea groups and their poor ability to self-associate. Remarkably, host 6 is able to perform solid-liquid as well as liquid-liquid extraction of G5. Finally, 6 provides an excellent structural model for the binding site of glycine betaine G4 encountered in natural systems.

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Triptycene‐Derived Calix[6]arenes: Synthesis, Structures, and Their Complexation with Fullerenes C₆₀ and C₇₀

Tian

Chen

2010

Chemistry A European J

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Two pairs of novel triptycene-derived calix[6]arenes 4a,b and 5a,b have been efficiently synthesized through both one-pot and two-step fragment-coupling strategies starting from 2,7-bis(hydroxymethyl)-1,8-dimethoxytriptycene 1. Subsequent demethylation of 4a,b and 5a,b with BBr(3) in dry dichloromethane gave the macrocyclic compounds 6a,b and 7a,b. Treatment of either 4a or 6a with AlCl(3) resulted in the same debutylated product 8, while 9 was similarly obtained from either 5a or 7a. Structural studies revealed that all of the macrocycles have well-defined structures with fixed conformations both in solution and in the solid state owing to the introduction of the triptycene moiety with a rigid three-dimensional (3D) structure, making them very different from their classical calix[6]arene counterparts. As a consequence, it was found that all of these the triptycene-derived calix[6]arenes could encapsulate small neutral molecules in their cavities in the solid state. Moreover, it was also found that the macrocycles 4b and 5b showed highly efficient complexation abilities toward fullerenes C(60) and C(70), forming 1:1 complexes with association constants ranging from (5.22+/-0.20) x 10(4) to (8.68+/-0.30) x 10(4) M(-1).

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Induced‐Fit Encapsulation by a 1,3,5‐Alternate Calix[6]arene

Cited by 6 publications

References 29 publications

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

A Biomimetic Heteroditopic Receptor for Zwitterions in Protic Media

Triptycene‐Derived Calix[6]arenes: Synthesis, Structures, and Their Complexation with Fullerenes C₆₀ and C₇₀

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Induced‐Fit Encapsulation by a 1,3,5‐Alternate Calix[6]arene

Cited by 6 publications

References 29 publications

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

Solvent‐ and Light‐Controlled Unidirectional Transit of a Nonsymmetric Molecular Axle Through a Nonsymmetric Molecular Wheel

A Biomimetic Heteroditopic Receptor for Zwitterions in Protic Media

Triptycene‐Derived Calix[6]arenes: Synthesis, Structures, and Their Complexation with Fullerenes C60 and C70

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Product

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Triptycene‐Derived Calix[6]arenes: Synthesis, Structures, and Their Complexation with Fullerenes C₆₀ and C₇₀