Vibrational relaxation of the N2O ν1 mode by Ar, N2, H2O, and NO

Abstract

The vibrational relaxation of the N₂O ν₁ symmetric stretch mode and the ν₂ bending mode due to collisions with Ar, N₂, and H₂O were studied at room temperature using a laser fluorescence technique. The V–V equilibration time constants between the ν₁ and ν₂ modes were measured to be 0.38, 0.26, and 3.0×10⁻³ μsec⋅atm with Ar, N₂, and H₂O, respectively, as the collision partner. The ν₂ V–T relaxation time constants of 12.1, 1.75, and 9.4×10⁻³ μsec⋅atm were measured, respectively, for collisions with Ar, N₂, and H₂O. In both relaxation processes H₂O was found to be an extremely efficient relaxer. The effects of N₂O–NO collisions were studied. The result suggested a fast V–V equilibration possibly due to the near resonance between the (11 ¹O) level of N₂O and the first excited vibrational level of NO.