Vibrational deactivation of carbon monoxide by hydrogen and nitrogen from 100 to 650 °K

Collisional quenching of carbon monoxide by hydrogen and nitrogen has been studied in the 100–650°K temperature range using the laser excited vibrational fluorescence method. The rate constant for CO–H2 deactivation increases smoothly with temperature from 2.6±0.3 sec−1·Torr−1 at 112°K to 170±15 sec−1·Torr−1 at 623°K. The vibration-to-vibration energy transfer results for CO–N2 mixtures (exothermic direction) show only a slight temperature dependence from 103 to 651°K with a broad maximum of 420±30 sec−1·Torr−1 in the temperature range 300–400°K. Comparison of our rates with high temperature shock tubes results show excellent agreement for the CO–H2 V → R,T process and only fair agreement for the CO–N2 V → V exchange process. This latter discrepancy may be partially due to the uncertainties involved in extracting V → V energy transfer rates from shock tube data.