Abstract book - Prof. Per Jensen, Ph.D. - Bergische Universität ...

Contributed Lectures, F2 99Vibrational assignment and vibronic interactionfor the nitrate radical NO 3 in the ground electronic stateEizi HirotaHirota E.The Graduate University for Advanced Studies, Hayama, Kanagawa 240-0193, JAPAN,ehirota@triton.ocn.ne.jpIshiwata et al. [1] determined three of the four normal mode frequencies from thedispersion spectra: ν 1 = 1060, ν 3 = 1480, and ν 4 = 380 in cm –1 . Ishiwata et al. [2] andKawaguchi et al. [3] later observed the ν 3 band at high resolution and derived the bandorigin to be 1492.3936 cm –1 . These results were supplemented by ν 2 = 762.327 cm –1 ,as reported by Friedl and Sander [4], to complete the assignment, which we shall referto as Assign I. In 2007 Stanton [5,6] proposed the ν 3 band to be near 1000 cm –1 , basedupon an ab initio calculation, and the 1492 cm –1 band was assigned to ν 3 + ν 4 : theassignment called Assign II. Kawaguchi et al. [7] searched for the basis in support ofAssign II, by reanalyzing the 1492 cm –1 band as the ν 3 + ν 4 and also by observingtransitions from the ν 4 fundamental state to the ν 3 + ν 4 state. Unfortunately, theiranalysis suffered from miss-assignment for the rotational quantum numbers N and K ofa part of the observed transitions and yielded some unrealistic results, which clearlyindicate Assign II unacceptable. In parallel with this study, I re-examined the 1492cm –1 band, by primarily paying attention to perturbations on K’ = 7 in the uppervibrational state of the band, the origin of which was previously not fully clarified [3],and convinced this time that the perturbations were caused by the interaction betweenthe ν 3 and 2ν 2 states. In fact, I succeeded in reproducing all the observed spectraincluding hot bands from the ν 4 state, thereby eliminating all the anomalous featuresreported in [7]. I conclude that the traditional vibrational assignment Assign I iscorrect, and I am suspecting that Stanton has overestimated the effects of vibronicinteractions.References[1] T. Ishiwata, I. Fujiwara, Y. Naruge, K. Obi, I. Tanaka, J. Phys. Chem. 87, 1349,1983.[2] T. Ishiwata, I. Tanaka, K. Kawaguchi, E. Hirota, J. Chem. Phys. 82, 2196, 1985.[3] K. Kawaguchi, E. Hirota, T. Ishiwata, I. Tanaka, J. Chem. Phys. 93, 951, 1990.[4] R. R. Friedl, S. P. Sander, J. Phys. Chem. 91, 2721, 1987.[5] J. F. Stanton, J. Chem. Phys. 126, 134309, 2007.[6] J. F. Stanton, Mol. Phys. 107, 1059, 2009.[7] K. Kawaguchi, N. Shimizu, R. Fujimori, J. Tang, T. Ishiwata, I. Tanaka, J. Mol.Spectrosc. 268, 85, 2011.