The low-temperature quenching of singlet molecular oxygen [O2(a 1? g )]

On the role of excited species in hydrogen combustion

“…Rate constants for interaction with O 2 , O, O 3 , N 2 and Ar have been discussed previously [34], in the present work some collisional efficiencies are updated and the mechanism is extended by hydrogen-containing collisional partners. IUPAC recommendations [65] were adopted for quenching by O 2 with the activation energy obtained by Billington and Borrell [85]. Their measurements are in a very good agreement with the results of Chatelet et al [86] and with the rate obtained later by Furui et al [87].…”

“…The values for N 2 and Ar used in our previous work [34] and based on the measurements of Clark and Wayne [80,92] were apparently overestimated due to experimental problems [81] discussed above in relation to reaction (31). The temperature dependence obtained for O 2 between 100 and 450 K [85] was assumed for other colliders with exception of atomic oxygen and hydrogen. In fact, the Arrhenius behavior of collisional quenching should not necessarily be expected; predictions of different models of E-V energy transfer [85,93,94] can be better presented as powerlaw temperature dependences.…”

“…Findlay and Snelling [88] approximated their measurements with the rate proportional to T 0.78 ± 0.32 , while Popov [28] adopted T 0.5 dependence based on theoretical calculations. One should note that description of the rate constant by T 0.5 dependence does not deviate more than by a factor of 2 from the Arrhenius expression with activation energy of 400 cal/mol [85] over the entire temperature range from room to combustion temperatures. Much higher activation energy was found by Borrell and Richards in their experiments with H 2 [95] and other collisional partners, SO 2 and HCl [96].…”

“…The temperature dependence obtained for O 2 between 100 and 450 K [85] was assumed for other colliders with exception of atomic oxygen and hydrogen. In fact, the Arrhenius behavior of collisional quenching should not necessarily be expected; predictions of different models of E-V energy transfer [85,93,94] can be better presented as powerlaw temperature dependences. Findlay and Snelling [88] approximated their measurements with the rate proportional to T 0.78 ± 0.32 , while Popov [28] adopted T 0.5 dependence based on theoretical calculations.…”

Cross Sections and Reaction Rates for Comparative Planetary Aeronomy

“…The overall rate of electronic relaxation of O 2 (a 1 g , v = 0) in Reaction (22) has been measured near room temperature in a number of investigations (Sander et al 2006), in liquid oxygen (Huestis et al 1974;Protz and Maier 1980;Faltermeier et al 1981;Wild et al 1982Wild et al , 1984, and more recently in gaseous oxygen between 100 and 500 K (Billingham and Borrell 1986;Chatelet et al 1986;Seidl et al 1991). The gas phase data in normal oxygen can be represented adequately by the formula k 22 (T ) = 0.14 × 10 −18 + 1.43 × 10 −18 (T /298).…”