Temperature Dependence of Nitrogen Broadening of the NO Fundamental Vibrational Band

We report measured N2-broadening coefficients, γ(T), of approximately 70 transitions of the ground electronic state fundamental vibration–rotation band (v= 1 ← 0) of NO at 183, 213, and 296 K. In addition to the broadening asymmetry previously observed between the2Π3/2and2Π1/2state transitions, we also observed for most of the2Π1/2transitions an increased broadening of thef–λ over thee–λ components. The temperature dependence of the broadening coefficients was characterized by the power law, γT= γ296(296/T)n. Our γ296values are on average systematically smaller than those of J. Ballardet al.[J. Mol. Spectrosc.127,70–82 (1988)] by 4.7%. We obtained an averagenof 0.708 ± 0.059 for the2Π1/2subband and 0.699 ± 0.067 for the2Π3/2subband. These averagenvalues fortuitously agree very well with the averagenvalues derived from measurements of NO–N2broadening cited above (n= 0.70) since individual differences are as large as 15%.