Vacuum-Ultraviolet Photolysis of N2O. IV. Deactivation of N(2D)

Abstract

The NO({:l) emission (B 'IT->X'II) observed during photolysis of N.O at 1470 A is due to a cherniluminescent reaction between N('D) and N.O. Transient measurements of this emission are analyzed to give the rate coefficients for removal of N (. D) by several simple molecules. Photolysis at 1236 A also produces NO(B 'IT), and the decay curves can be analyzed to give the same rate coefficients as observed at 1470 A, although there is evidence that an additional NO(B 'IT) production mechanism is involved. Quench'ng coefficients are also tabulated for N. (A 32;) and 0 (1 S), two other species investigated by the same technique.

Critically evaluated rate constants for gaseous reactions of several electronically excited species

“…is chemical in nature is well established (Lin & Kaufman, 1971;Dodge & Heicklen, 1971;Black et al, 1969Black et al, , 1975. The predominant reaction pathway appears to be to ground state products with a small contribution (0.3 %) in the channel producing NO(B2Il) (Slanger et aI., 1971;Herbelin & Cohen, 1973).…”

CRITICAL REVIEW OF N, N + , N + 2 , N ++ , And N ++ 2 MAIN PRODUCTION PROCESSES AND REACTIONS OF RELEVANCE TO TITAN'S ATMOSPHERE

“…The rate constant at 298 K recommended by Herron (4.0 × 10 −12 cm 3 s −1 ) is the average of the values determined by Fell et al (1981), Umemoto et al (1998b) and Takayanagi et al (1999) (see Table 3). The data by Black et al (1969) were disregarded as they differ too much with respect to the other measurements. Umemoto et al (1998b) and Takayanagi et al (1999) also studied the reaction with CD 4 , measuring at 298 K slightly lower rate constants for CD 4 than for CH 4 .…”

The photolysis of N2O at 1470 Å

“…The reactions of N(2D) and N(*S) with O2 can be ignored since they have rate constants 50 and 700 times smaller than reactions 10 and 11, respectively, at room temperatures [9,10]. In our experiments at low conversions, reaction (9) dominates and NO is produced.…”

“…NO production is reduced, O2 production is enhanced, and am( 0 2 ) rises. The rate constants k9 and klo are known to be 3 X and 1.8 X cm3/sec, respectively [9]. Thus, at 1%…”