Note to users. If you're seeing this message, it means that your browser cannot find this page's style/presentation instructions -- or possibly that you are using a browser that does not support current Web standards. Find out more about why this message is appearing, and what you can do to make your experience of our site the best it can be.

Science 5 December 2003:
Vol. 302. no. 5651, pp. 1736 - 1739
DOI: 10.1126/science.1091708
Prev | Table of Contents | Next

Reports

Probing the Threshold to H Atom Transfer Along a Hydrogen-Bonded Ammonia Wire

Christian Tanner, Carine Manca, Samuel Leutwyler*

We characterized the entrance channel, reaction threshold, and mechanism of an excited-state H atom transfer reaction along a unidirectionally hydrogen-bonded "wire" –O–H···NH3···NH3···NH3···N. Excitation of supersonically cooled 7-hydroxyquinoline·(NH3)3 to its vibrationless S1 state produces no reaction, whereas excitation of ammonia-wire vibrations induces H atom transfer with a reaction threshold {approx} 200 wave numbers. Further translocation steps along the wire produce the S1 state 7-ketoquinoline·(NH3)3 tautomer. Ab initio calculations show that proton and electron movement along the wire are closely coupled. The rate-controlling S1 state barriers arise from crossings of a {pi}{pi}* with a Rydberg-type {pi}{sigma}* state.

Department of Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012 Bern, Switzerland.

* To whom correspondence should be addressed. E-mail: samuel.leutwyler{at}iac.unibe.ch

Read the Full Text


THIS ARTICLE HAS BEEN CITED BY OTHER ARTICLES:
Ultrafast interfacial proton-coupled electron transfer..
B. Li, J. Zhao, K. Onda, K. D. Jordan, J. Yang, and H. Petek (2006)
Science 311, 1436-1440
   Abstract »    Full Text »    PDF »
Nonergodic and conformational control of the electron capture dissociation of protein cations.
K. Breuker, H. Oh, C. Lin, B. K. Carpenter, and F. W. McLafferty (2004)
PNAS 101, 14011-14016
   Abstract »    Full Text »    PDF »


To Advertise     Find Products

Science. ISSN 0036-8075 (print), 1095-9203 (online)