THEORETICAL AND EXPERIMENTAL CHARACTERIZATION OF THE $N_{2}O^{-} (X^{2} A')$ POTENTIAL ENERGY SURFACE
Loading...
Date
1976
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Collision induced dissociation reactions of $N_{2}O^{-}$ studied in beam experiments yields $D_{NO} = 0.43 \pm 0.1 eV$. From this result $D_{NN} = 5.13 \pm 0.1 eV$ and the adiabatic $EA = 0.22 \pm 0.1 eV$. Ab initio MCSCF/CI calculations with a better than double zeta basis set yields a minimum in $C_{s}$ symmetry: $(R_{NN} R_{NO-NNO} ) = (1-220$ \AA, 1.373 \AA, ${132.7^\circ})$. The vibrational frequencies are predicted to be $1030 \pm 60, 620 \pm 30$, and $1720 \pm 70 {cm^{-1}}$ . The computed dipole moment is $2.42 \pm 0-1$ debye. The negative ion surface was related to that of the ground state neutral by representing each by an angle-dependent Morse $function.^{1}$ All parameters were defined by the results of the present and previous $studies.^{2}$ The angular dependence of each function was modified to be that of the anharmonic, ab initio, bending potential energy curve. This representation of the surfaces yields a threshold of $0.47\pm 0.1$ eV at $(R^{*}_{NN}, R^{*}_{NO},\angle^{*}_{NNO})=$(1.17 \AA, 1.28\ \AA, $153^\circ)$ for the dissociative attachment process ${N_{2}}O +e^{-} = {N_{2}} + 0^{-}$. The threshold for the reverse, associative detachment, process is $0.25 \pm 0.1$ eV. A dynamic hindrance found for these processes will be discussed with the aid of a contour plot for the neutral surface superimposed on one for the negative surface.
Description
Author Institution: Chemistry Division, Argonne National Laboratory, Argonne, Illinois; Wright State University Dayton, Ohio, 45431
$^{1}$ W. E. Wentworth, E. Chen, and R. Freeman, J. Chem. Phys. 55, 2075 (1971). $^{2}$ P. J. Fortune, D. G. Hopper, B. J. Rosenberg, W. B. England, G. Das, A. C. Wahl, and T. O. Tiernan, "Potential Energy Surfaces for Air Triatomics. II., Results of SCF and Preliminary OVC Calculations", ARL TR 75-0202, VOL. II (AFSC), June 1975. Available from NTIS, Spring-field, Va., 22161. This research was supported, in part, by contracts from the Air Force Office of Scientific Research.
$^{1}$ W. E. Wentworth, E. Chen, and R. Freeman, J. Chem. Phys. 55, 2075 (1971). $^{2}$ P. J. Fortune, D. G. Hopper, B. J. Rosenberg, W. B. England, G. Das, A. C. Wahl, and T. O. Tiernan, "Potential Energy Surfaces for Air Triatomics. II., Results of SCF and Preliminary OVC Calculations", ARL TR 75-0202, VOL. II (AFSC), June 1975. Available from NTIS, Spring-field, Va., 22161. This research was supported, in part, by contracts from the Air Force Office of Scientific Research.