OBSERVATIONS ON THE LOW-LYING $ ^{2}B_{2} $ STATE OF $ NO_{2} $
Loading...
Date
1973
Journal Title
Journal ISSN
Volume Title
Publisher
Ohio State University
Abstract
The origin of the $^{2}B_{2} - ^{2}A_{1}$ transition of ${NO_{2}}^{ 1,2}$ is assigned to a near-infrared absorption band at 11 $956 cm^{-1}$ for $^{14}NO_{2}$ and 11 $984 cm^{-1}$ for $^{15}NO_{2}$. This band system has an irregular vibrational structure which, together with the anomalously large isotope origin shift, is attributed to vibronic coupling with higher vibrational levels of the $^{2}A_{1}$ ground state. A krypton ion laser (15 $449 cm^{-1})$ excites four transitions $^{q}R (13, 1), ^{q}R(3, 2), ^{q}R (4, 2)$ and $^{q}R(5, 2)$ in a band, $\nu_{0} = 15 455.3$ $cm^{-1}$, whose probable assignment is (050) - (000). Resonance fluorescence from the upper state occurs to ground state levels $n_{1} \nu_{1} + n_{2}\nu_{2}$ with $n_{1} = 0 - 2$ and $n_{2} = 0 - 5$. Analysis of the fluorescence gives approximate values of the rotational constants $A = 6.0$ and $1/2(B + C) = 0.345$ $cm^{-1}$ corresponding to red-degraded K- and N-structure. In view of the vibronic coupling these constants are not sufficient to determine the geometrical structure of the $^{2}B_{2}$ state.
Description
Author Institution: Department of Chemistry, University of Western Ontario, London