Unusual mechanisms can dominate reactions at hyperthermal energies: an example from O(3P) + HCl --> ClO + H

Jianming Zhang; Jon P Camden; Amy L Brunsvold; Hari P Upadhyaya; Timothy K Minton; George C Schatz

doi:10.1021/ja803080q

Unusual mechanisms can dominate reactions at hyperthermal energies: an example from O(3P) + HCl --> ClO + H

J Am Chem Soc. 2008 Jul 16;130(28):8896-7. doi: 10.1021/ja803080q. Epub 2008 Jun 24.

Authors

Jianming Zhang¹, Jon P Camden, Amy L Brunsvold, Hari P Upadhyaya, Timothy K Minton, George C Schatz

Affiliation

¹ Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.

PMID: 18572933
DOI: 10.1021/ja803080q

Abstract

An unusual mechanism in the reaction, O(3P) + HCl --> ClO + H, dominates at hyperthermal collision energies. This mechanism applies to collision geometries in which the H atom in the HCl molecule is oriented toward the reagent O atom. As the Cl-O bond forms, the H atom experiences a strong repulsive force from both the O and Cl atoms. The ClO product scatters forward with respect to the initial velocity of the O atom, and the H atom scatters backward. This mechanism accounts for more than half the reactive trajectories at energies >110 kcal mol-1, but it does not involve motion near the minimum energy path, which favors an SN2-like reaction mechanism where the H atom is oriented away from the reagent O atom during the collision.