INTRAMOLECULAR VIBRATIONAL ENERGY REDISTRIBUTION IN THE REACTION \\ H$_{3}^{+}$ + CO $\rightarrow$ H$_2$ + HCO$^+$/HOC$^+$
Loading...
Date
2009
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Observations of the rotational lines of HCO$^+$ produced in an extended negative glow discharge revealed high vibrational temperatures for the stretching vibrational modes, and non-thermal population distributions among the different $\ell$ levels of excited bending vibrational states., \textbf{127},074301 (2007).}$^{,}$, \textbf{248}, 26 (2008).} These results provide critical tests of our understanding of the dynamics and intramolecular vibrational energy redistribution (IVR) in this reaction process. The IVR in the HNC $\leftrightarrow$ HCN isomerization reaction, \textbf{458}, 285 (1999)} has been studied previously by \textit{ab initio} direct dynamics and vibration-mapping, \textbf{98}, 6936 (1994).} methods. An extension of the method used for the HNC/HCN isomerization reaction yields a new procedure for studying ``IVR in reactions'' which is applied to HCO$^{+}$/HOC$^{+}$ production in the H$_{3}^{+}$ + CO reaction, as described by the five-dimensional potential energy surface and pathways for this reaction reported recently by Li {\em et al.}, \textbf{129}, 244306 (2008).} Dynamics calculations have been performed for \lq\lq co-linear configuration" reactions in which H$_3^+$ approaches the C end of CO with a translational temperature of 20 K (a typical kinetic temperature of dark clouds) or 330 K (a typical translational temperature for ions in a glow discharge). As H$_3^+$ approaches CO with the lower-temperature translational energy, the hopping of H$^{+}$ to the CO moiety to form HCO$^{+}$ occurs over a period of about 100 fs, and the H--C stretching mode of the product HCO$^+$ is highly excited. This excitation can relax within the same vibrational ladder and/or be transferred to the bending mode through anharmonic coupling. Details of direct dynamics calculations for this process will be reported.
Description
T. Hirao, S. Yu, and T. Amano,\textit{J. Chem. Phys.T. Hirao, S. Yu, and T. Amano, \textit{J. Mol. Spectrosc.Y. Kumeda, Y. Minami, K. Takano, T. Taketsugu, and T. Hirano, \textit{J. Mol. Struct. (THEOCHEM)T. Hirano, T. Taketsugu, and Y. Kurita, \textit{J. Phys. Chem.H. Li, T. Hirano, T. Amano, and R.J. Le Roy, \textit{J. Chem. Phys.
Author Institution: Department of Chemistry, Faculty of Science, Ochanomizu University; Tokyo 112-8610, Japan; Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;
Author Institution: Department of Chemistry, Faculty of Science, Ochanomizu University; Tokyo 112-8610, Japan; Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada;