Vibrational deactivation of N2O(001) by N2O, CO, and Ar from 144–405 °K

Abstract

Vibrational deactivation of N2O(001) by N2O, CO, and Ar has been studied from 144 to 405 °K using the laser fluorescence method. The probability of vibration to vibration energy transfer, N2O(001) + CO(v=0) ? N2O(000) + CO(v=1) + ΔE = 81 cm−1, is 0.025 and is independent of temperature from 144 to 405 °K. We have performed theoretical calculations on this rate using the modified Sharma–Brau theory developed by Tam. The present results, together with previous experimental work at higher temperatures, suggest a good theoretical fit above room temperature, but not below. The deactivation of N2O(001) in collisions with N2O, CO, and Ar, N2O(001) + M → N2O(mnl0) + M + ΔE, has been determined to be 102 to 104 times slower than observed for the V→V exchange process. The N2O(001) intramolecular rates become smaller with decreasing temperature with the exception of the N2O self-relaxation rate. Below 250 °K this rate increases rapidly with decreasing temperature.

Collisional deactivation of N2O(001) studied by time-resolved infrared fluorescence

“…Doyennette et al used the N 2 O laser to prepare N 2 O͑00 0 1͒ for studies of self-relaxation and gas-surface collisions, 3,4 collisions with 14 N 2 and 15 N 2 over the temperature range 150-1200 K, 5 collisions with HCl over the temperature range 300-700 K, 6 and collisions with HBr over the temperature range 300-900 K. 7 Mehl et al 8 prepared N 2 O͑00 0 1͒ by the same method and studied the vibrational relaxation of the N 2 O͑00 0 1͒ by a series of deuterated methanes. Hancock and co-workers 9,10 prepared N 2 O͑00 0 1͒ by collisional pumping from CO ͑vϭ1͒ excited with a frequency-doubled CO 2 laser and measured the vibrational deactivation by N 2 O, CO, and Ar over the temperature range 144-405 K.…”

Shock tube studies of the N2O/Ar and N2O/H2/Ar systems

“…The data presented in Figures 3 and 4 indicate a definite enhancement in rate with the addition of O.Olyo and 0.1% Hz. Attempts to simulate this increase were made by numerically integrating reactions (1)- (6). The primary objective of these calculations was to see the effect of the two choices for k2 and ka on the value of kobs.…”

Collisional Deactivation of CO2(0001) and N2O(0001) by Toluene Isotopomers: Near-Resonant Energy Transfer from N2O(0001)

“…CO 2 has long been used in this role (see, for example, refs [1][2][3][4][5][6][7][8][9][10][11][12], but the studies of N 2 O began much more recently and are far less extensive. [13][14][15][16][17][18][19][20][21][22][23][24][25] Most experimental measurements have been confined to deactivation of both CO 2 and N 2 O excited to the (00 0 1) vibrational level of the asymmetric stretch mode, ν 3 .…”

“…They make an important comparative pair because they are isoelectronic, have the same mass, and have similar vibrational frequencies. CO 2 has long been used in this role (see, for example, refs −12), but the studies of N 2 O began much more recently and are far less extensive. − Most experimental measurements have been confined to deactivation of both CO 2 and N 2 O excited to the (00 0 1) vibrational level of the asymmetric stretch mode, ν 3 .…”