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Ultrafast photoactivation of C─H bonds inside water-soluble nanocages

Light energy absorbed by molecules can be harnessed to activate chemical bonds with extraordinary speed. However, excitation energy redistribution within various molecular degrees of freedom prohibits bond-selective chemistry. Inspired by enzymes, we devised a new photocatalytic scheme that preorgan...

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Autores principales: Das, Ankita, Mandal, Imon, Venkatramani, Ravindra, Dasgupta, Jyotishman
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Association for the Advancement of Science 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386559/
https://www.ncbi.nlm.nih.gov/pubmed/30801018
http://dx.doi.org/10.1126/sciadv.aav4806
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author Das, Ankita
Mandal, Imon
Venkatramani, Ravindra
Dasgupta, Jyotishman
author_facet Das, Ankita
Mandal, Imon
Venkatramani, Ravindra
Dasgupta, Jyotishman
author_sort Das, Ankita
collection PubMed
description Light energy absorbed by molecules can be harnessed to activate chemical bonds with extraordinary speed. However, excitation energy redistribution within various molecular degrees of freedom prohibits bond-selective chemistry. Inspired by enzymes, we devised a new photocatalytic scheme that preorganizes and polarizes target chemical bonds inside water-soluble cationic nanocavities to engineer selective functionalization. Specifically, we present a route to photoactivate weakly polarized sp(3) C─H bonds in water via host-guest charge transfer and control its reactivity with aerial O(2). Electron-rich aromatic hydrocarbons self-organize inside redox complementary supramolecular cavities to form photoactivatable host-guest charge transfer complexes in water. An ultrafast C─H bond cleavage within ~10 to 400 ps is triggered by visible-light excitation, through a cage-assisted and solvent water–assisted proton-coupled electron transfer reaction. The confinement prolongs the lifetime of the carbon-centered radical to enable a facile yet selective reaction with molecular O(2) leading to photocatalytic turnover of oxidized products in water.
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spelling pubmed-63865592019-02-23 Ultrafast photoactivation of C─H bonds inside water-soluble nanocages Das, Ankita Mandal, Imon Venkatramani, Ravindra Dasgupta, Jyotishman Sci Adv Research Articles Light energy absorbed by molecules can be harnessed to activate chemical bonds with extraordinary speed. However, excitation energy redistribution within various molecular degrees of freedom prohibits bond-selective chemistry. Inspired by enzymes, we devised a new photocatalytic scheme that preorganizes and polarizes target chemical bonds inside water-soluble cationic nanocavities to engineer selective functionalization. Specifically, we present a route to photoactivate weakly polarized sp(3) C─H bonds in water via host-guest charge transfer and control its reactivity with aerial O(2). Electron-rich aromatic hydrocarbons self-organize inside redox complementary supramolecular cavities to form photoactivatable host-guest charge transfer complexes in water. An ultrafast C─H bond cleavage within ~10 to 400 ps is triggered by visible-light excitation, through a cage-assisted and solvent water–assisted proton-coupled electron transfer reaction. The confinement prolongs the lifetime of the carbon-centered radical to enable a facile yet selective reaction with molecular O(2) leading to photocatalytic turnover of oxidized products in water. American Association for the Advancement of Science 2019-02-22 /pmc/articles/PMC6386559/ /pubmed/30801018 http://dx.doi.org/10.1126/sciadv.aav4806 Text en Copyright © 2019 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC). http://creativecommons.org/licenses/by-nc/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial license (http://creativecommons.org/licenses/by-nc/4.0/) , which permits use, distribution, and reproduction in any medium, so long as the resultant use is not for commercial advantage and provided the original work is properly cited.
spellingShingle Research Articles
Das, Ankita
Mandal, Imon
Venkatramani, Ravindra
Dasgupta, Jyotishman
Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title_full Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title_fullStr Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title_full_unstemmed Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title_short Ultrafast photoactivation of C─H bonds inside water-soluble nanocages
title_sort ultrafast photoactivation of c─h bonds inside water-soluble nanocages
topic Research Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6386559/
https://www.ncbi.nlm.nih.gov/pubmed/30801018
http://dx.doi.org/10.1126/sciadv.aav4806
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