LASER-INDUCED DISPERSED FLUORESCENCE-SPECTRA OF JET COOLED NO2 - THE COMPLETE SET OF VIBRATIONAL LEVELS UP TO 10000 CM-1 AND THE ONSET OF THE X2A1-A2B2 VIBRONIC INTERACTION

The laser induced dispersed fluorescence spectra (LIDFS) of jet cooled NO2 molecules in emission from 11 different vibronic levels located between 22 006 and 23 625 cm-1 was recorded. The corresponding variety of Franck-Condon accesses has allowed the observation of the complete set of the 191 lowest vibrational levels of the X approximately 2A1 ground state, located up to 10 000 cm-1. The vibrational band origins were measured to within typically 0.3 cm-1, assigned (n1, n2, n3), and fitted with a 24 coefficient Dunham expansion giving a typical residual error of 0.5 cm-1. Furthermore, the vibrationless A approximately 2B2 level has probably also been observed at 9737 cm-1. A perturbative model of the X approximately 2A1-A approximately 2B2 vibronic interaction has been used in order to calculate the energy shift of the high vibrational levels (around 10 000 cm-1) of the X approximately 2A1 state.