Vibrational deactivation studies of OH X²Π (v = 1–5) by N₂and O₂

Atmospheric Chemistry of CH3CH2OCH3: Kinetics and Mechanism of Reactions with Cl Atoms and OH Radicals

“…Reaction and results in not only OH radicals in the ground state but also in excited vibrational states with ν ≤ 4 and ν ≤ 9 for reaction and , respectively . However, it is safe to assume that excited OH will react exclusively with N 2 and O 2 and not any of the organics, since the rate coefficients for vibrational relaxation of OH by N 2 and O 2 are on the order of 10 −15 and 10 −13 cm 3 molecule −1 s −1 , respectively , and the mixing ratios of O 2 and N 2 are 4−5 orders of magnitude larger than those of the organic reactants.…”

“…Reaction (3) and (4) results in not only OH radicals in the ground state but also in excited vibrational states with ν ࣘ 4 and ν ࣘ 9 for reaction (3) and (4), respectively [25][26][27]. However, it is safe to assume that excited OH will react exclusively with N 2 and O 2 and not any of the organics, since the rate coefficients for vibrational relaxation of OH by N 2 and O 2 are on the order of 10 −15 and 10 −13 cm 3 molecule −1 s −1 , respectively [28], and the mixing ratios of O 2 and N 2 are 4−5 orders of magnitude larger than those of the organic reactants. The rate coefficients for O( 1 D) reaction with reference compounds and H 2 at 298 K are all of comparable magnitude, ß10 −10 cm 3 molecule −1 s −1 [29][30][31][32] (there is no rate coefficient available for the O( 1 D) reactions with the ethers).…”

Ketone photolysis in the presence of oxygen: A useful source of OH for flash photolysis kinetics experiments

“…When water is used as the hydrogen source then the vibrational distribution is bimodal [13]. Although the production of vibrationally excited species may be a possible disadvantage for thermal studies, the method has been used to good effect by Hynes and coworkers [14,15] and Yamasaki et al [16] This paper focuses on an alternative method for generating OH radicals as generically introduced in reaction (1) above and discussed here for the acetyl radical. The first step in the reaction is the formation of the excited peroxy species:…”

Theoretical determination of rate constants for vibrational relaxation and reaction of OH(XΠ2,v=1) with O(P3) atoms

“…4,5 In addition, there has been considerable interest in the rates of collisional nonreactive energy transfer processes involving OH, in particular, the rates of vibrational relaxation over a wide range of vibrational levels in collisions with stable molecules. [6][7][8][9][10][11][12][13][14] This work has been motivated, in part, by the need to understand OH vibrational emission in the upper atmosphere. Vibrationally excited OH is produced in the mesopause ͑at ϳ87 km altitude͒ through the reaction of ozone with atomic hydrogen ͓OH͑v Ͻ 9͔͒, 15 and in the stratosphere ͑20-40 km͒ and troposphere ͑ϳ10 km͒ through the reaction of O͑ 1 D͒ with water ͓OH͑v Ͻ 3͔͒.…”