The Reaction of NH2 with O

Combustion Chemistry of Nitrogen

“…The measurements at 295 K by Adamson et al (1994), who found kI5 (total) to be 3.9 x 10 13 cm 3 mol-l s-l , with about 5 to 8% branching into the NH + OH channel, are in reasonable agreement with the Dransfeld et al measurements. The branching ratio would be expected to have only a modest temperature dependence and (15c) would be expected to be the dominant channel at all temperatures.…”

THE C(3P) + NH3REACTION IN INTERSTELLAR CHEMISTRY. II. LOW TEMPERATURE RATE CONSTANTS AND MODELING OF NH, NH2, AND NH3ABUNDANCES IN DENSE INTERSTELLAR CLOUDS

“…The rate constant values come from various experimental studies. Adamson et al (1994) and Hack et al (1994) for the O + NH reaction, Adamson et al (1994) and Dransfeld et al (1985) for the O + NH 2 reaction and Dransfeld & Wagner (1987) and Whyte & Phillips (1983) for the N + NH 2 reaction, these rates being much higher than those used by Le Gal et al (2014) taken from the Ohio State University (OSU) and UMIST (Woodall et al 2007) astrochemical databases. The absence of CO depletion on grain surfaces leads to a lower N 2 H + abundance in the pure gas-phase model through the N 2 H + + CO reaction (slightly lower than the observed values (Dickens et al 2000;Ohishi et al 1992;Pratap et al 1997)), and therefore to low NH abundances through the DR reaction of N 2 H + .…”

Ab initio variational transition state theory calculations for the O+NH2 hydrogen abstraction reaction on the 4A′ and 4A″ potential energy surfaces

“…Figure 7 shows the calculated rate constants, including tunneling for both the 4 AЈ and 4 AЉ states as well as the total OϩNH 2 hydrogen abstraction rate constant ͑i.e., the sum of the two contributions͒. These three rate constants are well represented over the entire temperature range by the following three-parameter expressions: 4 Figure 7 also shows ͑short dashed line͒ the total rate constant for OϩNH 2 →products as measured at room temperature by Adamson et al 6 Assuming this rate to be independent of temperature, the abstraction reaction begins to compete only at temperatures around 2000 K or higher. These researchers estimate the branching into the NHϩOH product channel to be 5%-8% at room temperature.…”

“…More recently, Adamson et al, 6 using infrared kinetic spectroscopy in a fast flow system, determined the overall NH 2 disappearance rate constant to be ͑6.5Ϯ1.3͒ϫ10 Ϫ11 cm 3 molecule Ϫ1 s Ϫ1 and found that reaction ͑2͒ contributed only 5%-8% to the total reaction rate.…”