INFRARED SPECTRUM OF THE $Ar-HNH^{+}$ IONIC COMPLEX
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Date
1999
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
Rotationally resolved infrared spectra of the $\nu_{1}$ and $\nu_{3}$ N-H stretching vibrations of the $Ar-HNH^{+}$ radical ionic complex have been observed by means of photodissociation $spectroscopy.^{a}$ The analysis of the rotational structure shows that the complex has a $^{3}\Sigma^{-}$ ground electronic state with a linear or quasi-linear proton-bound structure $Ar-H-N-H^{+}$ characterized by an intermolecular center of mass separation of 3.085 {\AA}. The origins of the $\nu_{1}$ and $\nu_{3}$ bands were determined as 2803.65(2) and $3287.36(2) cm^{-1}$, and the frequency of the intermolecular stretch vibration, $\nu_{s}$, as $170.4(6) cm^{-1}$. Ab initio calculations performed at the UMP2 level of theory confirm that the quasi-linearity and the diradical character of $HNH^{+}$ in its electronic ground state are not changed upon Ar complexation. The calculated properties of the intermolecular bond of the complex $(D_{c}=1773 cm^{-1},R_{Ar-H}\sim 2.01 {\AA}, \nu_{s}\sim 185 cm^{-1})$ and the predicted complexation induced frequency shifts for $\nu_{1}$ and $\nu_{3}$ are in good agreement with the experimental results.
Description
$^{a}$O. Dopfer, S.A. Nizkorodov, R.V. Olkhov, J.P. Maier, and K. Harada. J. Phys. Chem. A102, 10017 (1998).
Author Institution: Institut f\""{u}r Physikalische Chemie, Universit\""{a}t Basel; Institute for Molecular Science, Myodaiji
Author Institution: Institut f\""{u}r Physikalische Chemie, Universit\""{a}t Basel; Institute for Molecular Science, Myodaiji