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(mn^l0) + 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.