Time-resolved infrared fluorescence from 2ν₁ and 2ν₈ modes of CF₂Cl₂ excited by a CO₂ laser

Abstract

Infrared fluorescence has been observed from the overtones and combination bands of ν ₁ and ν ₈ on pumping either of these modes of CF₂Cl₂ by a CO₂ laser. Excitation of the ν ₈ mode gives fluorescence from 2 ν ₁/( ν ₁ + ν ₆) and 2 ν ₈ modes at 4.6 and 5.4 µm, respectively. The intensity of 4.6 µm fluorescence showed a quadratic dependence on the pressure of CF₂Cl₂. A decay rate constant of (2.76± 0.55) × 10⁴ s^-1 Torr^-1 was obtained for this emission band and it has been assigned to intermode energy outflow from the ν ₁ and ν ₆ modes. The possible pathways of populating the ν ₁ and ν ₆ modes are discussed.