FIRST HIGH-RESOLUTION SPECTRA AND ROTATIONAL CONSTANTS OF $BrNO_{2}$ (NITRYL-BROMIDE)
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Date
1997
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Publisher
Ohio State University
Abstract
Nitryl bromide ($BrNO_{2}$) formed by heterogeneous reaction on polar stratospheric clouds and on sea-salt particles in the marine troposphere. However, no rotationally resolved spectra have been reported up to now, and nothing is known about rotational constants, structure, and force field of $BrNO_{2}$. In fact, the only observations of $BrNO_{2}$ in the gas phase were possible using flow experiments with gaseous $N_{2}O_{5}$ flowing over NaBr particles. In this study, a different approach was used. By reaction of highly diluted gaseous $ClNO_{2}$ with an aqueous $Br^{-}$ solution, $BrNO_{2}$ was formed and trapped at low temperature. The crude product was purified by trap-to-trap condensations and fractional sublimation in vacuo. High-resolution infrared spectra of the $\nu_{4}$ band of $BrNO_{2}$ around $1660 cm^{-1}$ were measured with resolutions of up to $0.002 cm^{-1}$, using the Bruker IFS-120HR FTS at University of Hannover. For the first time, rotational constants for the $^{79}BrNO_{2}$ and $^{81}BrNO_{2}$ isotopomers were determined for the $\nu_{4}$ and ground vibrational states. The constants were used for determination of a first substitution structure and, together with infrared band centers, the harmonic force field of $BrNO_{2}$.
Description
Author Institution: Institute of Environmental Physics, University of Bremen; Institute of Physical Chemistry, University of Hannover; Institute of Physical Chemistry, Fraunhofer-Institute of Toxicology and Aerosol Research