Vibrational energy transfer of NO (X 2Π, v=2 and 1)

Abstract

A two‐laser (ir overtone pump and uv laser‐induced fluorescence probe) technique has been used to measure vibrational relaxation rate coefficients for NO (X ²Π, v=2 and 1) with various collision partners at room temperature. The relaxation of v=2 by NO, H₂, and NH₃ has also been measured at 240 K. The relaxation of v=2 by NO is dominated by vibration‐to‐vibration (V–V) transfer and this process has not previously been measured below room temperature. The probability for V–V transfer increases with decreasing temperature, indicating that attractive forces play a key role in this process. Different physical mechanisms for NO vibrational energy transfer are discussed in light of the available data.