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 8 August 2008:
Vol. 321. no. 5890, pp. 826 - 830
DOI: 10.1126/science.1157617
Prev | Table of Contents | Next

Reports

The Role of Excited-State Topology in Three-Body Dissociation of sym-Triazine

John D. Savee,1 Vadim A. Mozhayskiy,2 Jennifer E. Mann,1 Anna I. Krylov,2* Robert E. Continetti1*

Molecular fragmentation into three products poses an analytical challenge to theory and experiment alike. We used translational spectroscopy and high-level ab initio calculations to explore the highly debated three-body dissociation of sym-triazine to three hydrogen cyanide molecules. Dissociation was induced by charge exchange between the sym-triazine radical cation and cesium. Calculated state energies and electronic couplings suggest that reduction initially produces a population of sym-triazine partitioned between the 3s Rydberg and {pi}* <- n electronically excited manifolds. Analysis of the topology of these manifolds, along with momentum correlation in the dissociation products, suggests that a conical intersection of two potential energy surfaces in the 3s Rydberg manifold leads to stepwise dissociation, whereas a four-fold glancing intersection in the {pi}* <- n manifold leads to a symmetric concerted reaction.

1 Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA.
2 Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.

* To whom correspondence should be addressed. E-mail: krylov{at}usc.edu (A.I.K.); rcontinetti{at}ucsd.edu (R.E.C.)

Read the Full Text

To Advertise     Find Products

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