Laser double resonance measurements of vibrational energy transfer rates and mechanisms in HF( v = 2)

Overtone vibration-laser double resonance studies of HF(v = 2) yield self-relaxation rate constants for v = 2 and v = 1 of k2 = (19.8±1.0) ×10−12 cm3 molecule−1 s−1 and k1 = (1.46±0.1) ×10−12 cm3 molecule−1s−1, respectively. These experiments indicate that the fraction of HF(v = 2) molecules relaxing via vibration-to-vibration energy transfer is only 0.35±0.10, in sharp contrast to trajectory and scaling calculations which predict the dominance of this pathway over vibration-to-translation, rotation energy transfer.