Cargando…

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...

Descripción completa

Detalles Bibliográficos
Autores principales: 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
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2016
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
_version_ 1782426470956662784
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
work_keys_str_mv AT wangyuping oligorotaxaneradicalsunderorders
AT frasconimarco oligorotaxaneradicalsunderorders
AT liuweiguang oligorotaxaneradicalsunderorders
AT sunjunling oligorotaxaneradicalsunderorders
AT wuyilei oligorotaxaneradicalsunderorders
AT nassarmajeds oligorotaxaneradicalsunderorders
AT botrosyoussryy oligorotaxaneradicalsunderorders
AT goddardwilliama oligorotaxaneradicalsunderorders
AT wasielewskimichaelr oligorotaxaneradicalsunderorders
AT stoddartjfraser oligorotaxaneradicalsunderorders