Redox-Switchable Resorcin[4]arene Cavitands: Molecular Grippers

Pochorovski, Igor; Ebert, Marc‐Olivier; Gisselbrecht, Jean‐Paul; Boudon, Corinne; Schweizer, W. Bernd; Diederich, François

doi:10.1021/ja306473x

Cited by 73 publications

(100 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…

…”

mentioning

confidence: 99%

“…We analyzed their electronic, conformational, and binding properties by cyclic voltammetry, UV/Vis spectroelectrochemistry, EPR and transient absorption spectroscopy, in conjunction with DFT calculations. The utility of UV/Vis spectroelectrochemistry and EPR spectroscopy in evaluating the conformational features of resorcin [4]arene cavitands is demonstrated. Guest binding properties were found to be enhanced in the SQ state as compared to the quinone (Q) or the hydroquinone (HQ) states of the cavitands.…”

mentioning

confidence: 99%

“…The development of semiquinone-based resorcin [4]arene cavitands expands the toolbox of switchable molecular grippers by introducing the first paramagnetic representatives.…”

mentioning

confidence: 99%

“…4,7,8,22,23 Resorcin [4]arenes are suitable platforms for the development of molecular grippers, owing to their capability to adopt bistable, open (kite) and closed (vase) conformations. 4,24,25 The vase-kite equilibrium can be influenced by various stimuli, such as solvent choice, 26,27 temperature, 28 pH, 29 metal-ion concentration, 30 or redox processes. 24,25,31 The development of cavitands that can respond to electrical or electromagnetic stimuli is required for future applications of resorcin [4]arene-based molecular grippers.…”

mentioning

confidence: 99%

See 3 more Smart Citations

Paramagnetic Molecular Grippers: The Elements of Six-State Redox Switches

Milić

Zalibera

Pochorovski

et al. 2016

J. Phys. Chem. Lett.

Self Cite

100

View full text Add to dashboard Cite

The development of semiquinone-based resorcin[4]arene cavitands expands the toolbox of switchable molecular grippers by introducing the first paramagnetic representatives. The semiquinone (SQ) states were generated electrochemically, chemically, and photochemically. We analyzed their electronic, conformational, and binding properties by cyclic voltammetry, ultraviolet/visible (UV/vis) spectroelectrochemistry, electron paramagnetic resonance (EPR) and transient absorption spectroscopy, in conjunction with density functional theory (DFT) calculations. The utility of UV/vis spectroelectrochemistry and EPR spectroscopy in evaluating the conformational features of resorcin[4]arene cavitands is demonstrated. Guest binding properties were found to be enhanced in the SQ state as compared to the quinone (Q) or the hydroquinone (HQ) states of the cavitands. Thus, these paramagnetic SQ intermediates open the way to six-state redox switches provided by two conformations (open and closed) in three redox states (Q, SQ, and HQ) possessing distinct binding ability. The switchable magnetic properties of these molecular grippers and their responsiveness to electrical stimuli has the potential for development of efficient molecular devices.

show abstract

“…

…”

mentioning

confidence: 99%

mentioning

confidence: 99%

“…The development of semiquinone-based resorcin [4]arene cavitands expands the toolbox of switchable molecular grippers by introducing the first paramagnetic representatives.…”

mentioning

confidence: 99%

mentioning

confidence: 99%

See 2 more Smart Citations

Paramagnetic Molecular Grippers: The Elements of Six-State Redox Switches

Milić

Zalibera

Pochorovski

et al. 2016

J. Phys. Chem. Lett.

Self Cite

100

View full text Add to dashboard Cite

show abstract

“…As initially encountered by Cram et al (4), deep cavitands are dynamic and interconvert between two conformations in organic media: a receptive "vase" form and the unreceptive "kite" form as its dimeric "velcrand" (Fig. 1) (4)(5)(6)(7)(8). Stacking of aromatic surfaces in the velcrand buries one face of each kite and is driven by a generalized solvophobic effect.…”

mentioning

confidence: 91%

Recognition and sequestration of ω-fatty acids by a cavitand receptor

Mosca

Ajami

Rebek

2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

One of the largest driving forces for molecular association in aqueous solution is the hydrophobic effect, and many synthetic receptors with hydrophobic interiors have been devised for molecular recognition studies in water. Attempts to create the longer, narrower cavities appropriate for long-chain fatty acids have been thwarted by solvophobic collapse of the synthetic receptors, giving structures that have no internal spaces. The collapse generally involves the stacking of aromatic panels onto themselves. We describe here the synthesis and application of a deep cavitand receptor featuring "prestacked" aromatic panels at the upper rim of the binding pocket. The cavitand remains open and readily sequesters biologically relevant long-chain molecules-unsaturated ω-3, -6, and -9 fatty acids and derivatives such as anandamide-from aqueous media. The cavitand exists in isomeric forms with different stacking geometries and n-alkanes were used to characterize the binding modes and conformational properties. Long alkyl chains are accommodated in inverted J-shaped conformations. An analogous cavitand with electron-rich aromatic walls was prepared and comparative binding experiments indicated the role of intramolecular stacking in the binding properties of these deep container molecules. (1) and other open-ended host structures (2, 3) that more or less fold around their guest targets. As initially encountered by Cram et al. (4), deep cavitands are dynamic and interconvert between two conformations in organic media: a receptive "vase" form and the unreceptive "kite" form as its dimeric "velcrand" (Fig. 1) (4-8). Stacking of aromatic surfaces in the velcrand buries one face of each kite and is driven by a generalized solvophobic effect. The vase can be rigidified by covalent bonds (9-13) but in water the dynamic cavitands collapse into velcrands through the more specific hydrophobic effect. The presence of appropriate guests shifts the equilibrium to the vase conformation: The guest must fit into, fill, and solvate the cavitand host's hydrophobic interior. Binding of guest molecules by container compounds is often dependent on the volume of the host. Recognition of long-chain, linear hydrocarbons by biological receptors and synthetic supramolecular hosts generally involves ∼55% volume occupancy and relatively low surface complementarity (14-16). Cavitands with a depth of 1 nm are readily prepared and bind medium-chain n-alkanes, from octane (C 8 ) to decane (C 10 ). Longer alkanes such as tetradecane (C 14 ) often induce the formation of dimeric, capsule-like assemblies in which the alkyls assume compressed conformations involving folding and coiling (17, 18). Common, long-chain fatty acids bearing saturated or unsaturated alkyl chains are not readily accommodated in dimeric capsules (19,20) or in the vase forms of typical cavitands. Here, we report a deeper cavitand with a longer, narrower cavity that readily sequesters physiologically relevant fatty acids and derivatives from aqueous media. ResultsSynthesis and Characte...

show abstract

Molecular Tweezers

2018

Molecular Devices

View full text Add to dashboard Cite

Redox-Switchable Resorcin[4]arene Cavitands: Molecular Grippers

Cited by 73 publications

References 44 publications

Paramagnetic Molecular Grippers: The Elements of Six-State Redox Switches

Paramagnetic Molecular Grippers: The Elements of Six-State Redox Switches

Recognition and sequestration of ω-fatty acids by a cavitand receptor

Molecular Tweezers

Contact Info

Product

Resources

About