| Popis: |
By exciting NO2 with a narrow band (0.035 cm−1 FWHM) tunable dye laser in the region of 5935 A, an extensive analysis of the K = 0, 1, and 2 subbands of a vibronic transition has been carried out. The analysis of this transition proves that the upper state has the electronic symmetry 2B2. The origin of the analyzed band is placed at 16 849.48 cm−1 and the following molecular constants provide a best fit to the measured line positions: Av = 7.85 cm−1, Bv = 0.451 cm−1, Cv = 0.394 cm−1, and ϵbb + ϵcc = −0.0877 cm−1. The band exhibits a number of obvious perturbations with a marked intensity falloff for increasing N and K values. Large centrifugal distortion constants are required, apparently caused by N-dependent perturbations. A large inertial defect, Δ = 3.26 amu A 2 , is also found. By attributing the inertial defect to the vibrational dependence of Av, we estimate the geometry for the NO22B2 excited state extrapolated to the vibrational origin to be r 0 = 1.31 A and θ0 = 111°. |
