Water-wire catalysis in photoinduced acid–base reactions
- Creators
- Kwon, Oh-Hoon
- Mohammed, Omar F.
Abstract
The pronounced ability of water to form a hyperdense hydrogen (H)-bond network among itself is at the heart of its exceptional properties. Due to the unique H-bonding capability and amphoteric nature, water is not only a passive medium, but also behaves as an active participant in many chemical and biological reactions. Here, we reveal the catalytic role of a short water wire, composed of two (or three) water molecules, in model aqueous acid–base reactions synthesizing 7-hydroxyquinoline derivatives. Utilizing femtosecond-resolved fluorescence spectroscopy, we tracked the trajectories of excited-state proton transfer and discovered that proton hopping along the water wire accomplishes the reaction more efficiently compared to the transfer occurring with bulk water clusters. Our finding suggests that the directionality of the proton movements along the charge-gradient H-bond network may be a key element for long-distance proton translocation in biological systems, as the H-bond networks wiring acidic and basic sites distal to each other can provide a shortcut for a proton in searching a global minimum on a complex energy landscape to its destination.
Additional Information
© 2012 the Owner Societies. Received 29 Nov 2011, Accepted 01 Feb 2012. First published on the web 22 Feb 2012. We are grateful to Prof. Ahmed H. Zewail for his persistent encouragement for the work and careful reading of the manuscript. We thank Prof. B. Stoltz for allowing access to his facilities for synthesis of chemicals and Dr. Sang Tae Park for reading of the manuscript. This work was supported by the National Science Foundation.Attached Files
Published - Kwon2012p17310Physical_chemistry_chemical_physics_PCCP.pdf
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Additional details
- Eprint ID
- 32015
- Resolver ID
- CaltechAUTHORS:20120621-134944440
- NSF
- Created
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2012-06-21Created from EPrint's datestamp field
- Updated
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2021-11-09Created from EPrint's last_modified field