Stimulus-Responsive Azobenzene Supramolecules: Fibers, Gels, and Hollow Spheres

Lee, Sumi; Oh, Seungwhan; Lee, Joosub; Malpani, Yashwardhan R.; Jung, Young‐Sik; Kang, Baotao; Lee, Jin Yong; Ozasa, Kazunari; Isoshima, Takashi; Lee, Sang-Yun; Hara, Masahiko; Hashizume, Daisuke; Kim, Jong-Man

doi:10.1021/la400159m

Cited by 105 publications

(208 citation statements)

References 61 publications

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“…18). 257 The breakdown of aggregates may result in a simple solution of the constituent compounds. However, it is also possible for new, smaller assemblies to be generated, as illustrated by Yagai et al in a study of the melamine derivative 13.…”

Section: Conformational Changesmentioning

confidence: 99%

Gels with sense: supramolecular materials that respond to heat, light and sound

2016

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. (2016) 'Gels with sense : supramolecular materials that respond to heat, light and sound.', Chemical society reviews., 45 (23). pp. 6546-6596. Further information on publisher's website:https://doi.org/10.1039/C6CS00435KPublisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Advances in the field of supramolecular chemistry have made it possible, in many situations, to reliably engineer soft materials to address a specific technological problem. Particularly exciting are "smart" gels that undergo reversible physical changes on exposure to remote, non-invasive environmental stimuli. This review explores the development of gels which are transformed by heat, light and ultrasound, as well as other mechanical inputs, applied voltages and magnetic fields. Focusing on small-molecule gelators, but with reference to organic polymers and metal-organic systems, we examine how the structures of gelator assemblies influence the physical and chemical mechanisms leading to thermo-, photo-and mechano-switchable behaviour. In addition, we evaluate how the unique and versatile properties of smart materials may be exploited in a wide range of applications, including catalysis, crystal growth, ion sensing, drug delivery, data storage and biomaterial replacement.

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Section: Conformational Changesmentioning

confidence: 99%

Gels with sense: supramolecular materials that respond to heat, light and sound

2016

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“…In this study, it is the π-π stacking of the azobenzene moiety that provides additional stabilization of gelator 1 into the non-helical fiber arrangement. 19 Other important works have shown reversible helical switching in supramolecular systems in response to photoisomerization of azobenzene moieties. Addition of HCl can be used to dissociate the chiral analyte to re-initiate the non-helical stacking configuration of gelator 1.…”

Section: Resultsmentioning

confidence: 99%

Chirality control of self-assembled achiral nanofibers using amines in their solid state

et al. 2015

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Although there are numerous examples of helical and spiral conformations in nature, including plant tendrils, snail shells, and even collagen, the occurrence of supramolecular systems that are able to reversibly undergo solid-to-solid helical transformation based on environmental chiral triggers is rare. In this work, we present a supramolecular, non-helical nanofiber which shows a distinct helical rearrangement in the presence of specific diamines and monoamines, such as cyclohexanediamines, alanine, lysine, and phenylalanine, depending on the molecular chirality of the surrounding analytes. A detailed investigation on the structural organization of the nanofibers using SEM and CD spectra analysis confirmed the repeatable and reversible nature of this amplification of chiral information. Further preparation of an electrospun nanofiber film was demonstrated for distinguishing chiral diamines and monoamines in solution by film immersion and CD analysis, which is the first example of amplification of chiral information in the solid-state using electrospun nanofiber films. With this system, we could demonstrate a reusable means for detecting the molecular chirality, which also provided a unique example of reversible control of solid state rearrangement in supramolecular helicity.

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“…Upon UV irradiation, 1 D nanomaterials could disappear completely. The responsive materials may receive considerable interest as controlled release vehicles for drug delivery or electro-optical devices [30,31].…”

Section: Introductionmentioning

confidence: 99%