Report

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

See allHide authors and affiliations

Science  05 Dec 2003:
Vol. 302, Issue 5651, pp. 1736-1739
DOI: 10.1126/science.1091708

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

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 ≈ 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 ππ* with a Rydberg-type πσ* state.

View Full Text