Knowledge Bank

Rotational analysis of the nitrogen dioxide visible system has revealed extensive spin perturbations. An example of the complexity of the spin perturbation is provided by the $Ka\prime =0$ subband of the 612.5 nm band: the lower energy spin components are strongly perturbed while the higher energy spin components are relatively unperturbed although the two spin states are expected to have identical symmetry $(E1/2)$. Possible perturbation mechanisms are discussed and the perturbation is compared to that of $ClO2$ which also exhibits a spin state-dependent $perturbation.2$ $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$D.L. Months. B. Soep, and R.N. Zare, J. Mol. Spectrosc, 77, 402-428 (1979). $\mathrm{<mrow\; data-mjx-texclass="ORD">2</mrow>}$S. Michielsen, A.J. Merer, S.A, Rice, F.A. Novak, K.F. Freed, and Y. Hamada, J. Chem. Phys, 74, 3089-3101 (1981).