Laser photolysis of ozone in the presence of ammonia: Vibrationally excited OH radicals

Relaxation of Vibrationally Excited OH Radical by SO

“…In the Supporting Information, we have included tables (Tables S8 and S9 and Figures S4 and S5) with the experimental data for vibrational relaxation of OH in collision with O 2 , , CO 2 , , CH 4 , ,, ,, N 2 O, H 2 O, , CH 3 SH, and NH 3 . ,,, ,,, …”

“…It appears in vibrationally excited states in different chemical reactions. For example, the reaction where v and j are vibrational and rotational quantum numbers, respectively, is well known to be a source of OH­( v ≤ 9). − Other reactions producing vibrationally excited OH are ,− and Despite the low water vapor content of the stratosphere, below 70 km, reaction () is an important source of OH radicals at that atmospheric level. ,, In atmospheric conditions, the O­( 1 D) atoms are produced in the O 3 photodissociation according to the reaction Vibrationally excited OH radical are also produced by the chemical reaction − The vibrational excitation of the OH radical produces changes in the physical and chemical properties of this species. Therefore, the modeling of processes in the atmosphere, combustion, lasers, and plasma requires the knowledge of relaxation mechanisms leading to the quenching of the vibrational energy of this species.…”

“…As a consequence of the recognized importance of knowing the characteristics of the relaxation processes of the vibrationally excited OH, a significant number of theoretical ,, and experimental studies ,,,,− ,− have been carried out to determine the rate coefficients of the collisional relaxation processes of the vibrationally excited OH radical. The study of the available experimental data on the relaxation of the vibrationally excited OH radical led Kohno and collaborators to propose a polarity classification for the OH collision partners.…”

“…The study of the available experimental data on the relaxation of the vibrationally excited OH radical led Kohno and collaborators to propose a polarity classification for the OH collision partners. Accordingly, polar molecules such as H 2 O, , NH 3 , ,,,, and CH 3 SH are considered as efficient relaxant, less polar, and some nonpolar molecules, e.g., O 2 , ,,− CO 2 , ,,,− N 2 O, and CH 4 ,,, are classified as intermediate relaxants, while monoatomic He, , Ar, , and the nonpolar molecules H 2 , N 2 , are in the class of collision partners with low quenching efficiency . Despite this interest, we are unaware of theoretical or experimental studies devoted to the vibrational relaxation of the OH radical in collision with the SO molecule, a radical that plays a significant role in interstellar and circumstellar, atmospheric, and combustion chemistry …”

Application of a new method to the determination of rate constants: Examination of the effect of noise on the data

“…However, this type of analysis does not always derive accurate rate constants for the relaxation. The present integrated method, on the other hand, can be applied without any complications to obtain rate constants for the profiles of C and D in scheme (9). All the parameters are determined by the analysis using the following equations: Figure 3.…”