High-pressure Raman study of vibrational relaxation in N2O

The vibrational widths of the ν₁ and ν₃ Raman bands of N₂O were determined at pressures ranging from 8 bar to 2 kbar and temperatures varied from 25 to 150°C. The different dephasing theories including motional narrowing collisional models and resonant vibrational energy transfer theory were tested. A comparison of the theoretical predictions with the experimental data indicates the resonance VV transfer represents the dominant broadening mechanism. The observed frequency shifts between isotropic and anisotropic components of the bands were interpreted in terms of dipole-dipole interactions in dense N₂O.