Vibration–Vibration energy exchange between N₂O and CO

Abstract

The temperature dependence of the vibration-vibration energy transfer between the mode of l5Nl4NO and the first vibrational level of CO was determined over a range of 680 to 1300°K using a shock tube. Several mixtures of 15NI4NO-CO were tested, diluted in 95% Ar.The resulting exothermic transfer probabilities for the reaction, 15N14N0(001) + CO(0) -+ 15N14N0(000) + CO (1) are compared to previous work on N,O-CO.The results for 15N14NO-C0 exhibit a more pronounced direct temperature dependence than for NZO-CO even though the process has a closer resonance (AE = 59 cm-1 for 15N14NO-C0 and AE = 81 cm-1 for NzO-CO). Past theoretical studies [ 1-71 supported by experimental investigations IS, 91show that the participation of long-range molecular force interactions results in a different temperature dependence for the transfer probabilities than predicted using short-range force interactions. Long-range forces such as dipole-dipole or dipole-quadrupole theoretically yield an inverse temperature dependence of the transfer probabilities as opposed to the direct temperature dependence predicted using short-range forces. In addition, the effect of long-range forces tends to be more pronounced as the nonresonance of the collison partners AE that for dipole-dipole interactions the inverse temperature dependence will not manifest itself until the energy defect is much smaller. To investigate this further a study of the vibration-vibration relaxation between the v3 mode of * Present address: