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Oligorotaxane Radicals under Orders
[Image: see text] A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
American Chemical Society
2016
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827492/ https://www.ncbi.nlm.nih.gov/pubmed/27163033 http://dx.doi.org/10.1021/acscentsci.5b00377 |
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author | Wang, Yuping Frasconi, Marco Liu, Wei-Guang Sun, Junling Wu, Yilei Nassar, Majed S. Botros, Youssry Y. Goddard, William A. Wasielewski, Michael R. Stoddart, J. Fraser |
author_facet | Wang, Yuping Frasconi, Marco Liu, Wei-Guang Sun, Junling Wu, Yilei Nassar, Majed S. Botros, Youssry Y. Goddard, William A. Wasielewski, Michael R. Stoddart, J. Fraser |
author_sort | Wang, Yuping |
collection | PubMed |
description | [Image: see text] A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY(•+) radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne–azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. |
format | Online Article Text |
id | pubmed-4827492 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | American Chemical Society |
record_format | MEDLINE/PubMed |
spelling | pubmed-48274922016-05-09 Oligorotaxane Radicals under Orders Wang, Yuping Frasconi, Marco Liu, Wei-Guang Sun, Junling Wu, Yilei Nassar, Majed S. Botros, Youssry Y. Goddard, William A. Wasielewski, Michael R. Stoddart, J. Fraser ACS Cent Sci [Image: see text] A strategy for creating foldameric oligorotaxanes composed of only positively charged components is reported. Threadlike components—namely oligoviologens—in which different numbers of 4,4′-bipyridinium (BIPY(2+)) subunits are linked by p-xylylene bridges, are shown to be capable of being threaded by cyclobis(paraquat-p-phenylene) (CBPQT(4+)) rings following the introduction of radical-pairing interactions under reducing conditions. UV/vis/NIR spectroscopic and electrochemical investigations suggest that the reduced oligopseudorotaxanes fold into highly ordered secondary structures as a result of the formation of BIPY(•+) radical cation pairs. Furthermore, by installing bulky stoppers at each end of the oligopseudorotaxanes by means of Cu-free alkyne–azide cycloadditions, their analogous oligorotaxanes, which retain the same stoichiometries as their progenitors, can be prepared. Solution-state studies of the oligorotaxanes indicate that their mechanically interlocked structures lead to the enforced interactions between the dumbbell and ring components, allowing them to fold (contract) in their reduced states and unfold (expand) in their fully oxidized states as a result of Coulombic repulsions. This electrochemically controlled reversible folding and unfolding process, during which the oligorotaxanes experience length contractions and expansions, is reminiscent of the mechanisms of actuation associated with muscle fibers. American Chemical Society 2016-02-01 2016-02-24 /pmc/articles/PMC4827492/ /pubmed/27163033 http://dx.doi.org/10.1021/acscentsci.5b00377 Text en Copyright © 2016 American Chemical Society This is an open access article published under an ACS AuthorChoice License (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html) , which permits copying and redistribution of the article or any adaptations for non-commercial purposes. |
spellingShingle | Wang, Yuping Frasconi, Marco Liu, Wei-Guang Sun, Junling Wu, Yilei Nassar, Majed S. Botros, Youssry Y. Goddard, William A. Wasielewski, Michael R. Stoddart, J. Fraser Oligorotaxane Radicals under Orders |
title | Oligorotaxane Radicals under Orders |
title_full | Oligorotaxane Radicals under Orders |
title_fullStr | Oligorotaxane Radicals under Orders |
title_full_unstemmed | Oligorotaxane Radicals under Orders |
title_short | Oligorotaxane Radicals under Orders |
title_sort | oligorotaxane radicals under orders |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4827492/ https://www.ncbi.nlm.nih.gov/pubmed/27163033 http://dx.doi.org/10.1021/acscentsci.5b00377 |
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