Journal of Chemical Physics, Vol.109, No.23, 10217-10221, 1998
The near-infrared bands of NO2 observed by high-resolution Fourier-transform spectroscopy
Fourier-transform absorption spectra of NO2 at 298 K were recorded between 9000-15000 cm(-1) at Doppler-limited resolution (0.012 cm(-1)), in the region near the (A) over tilde B-2(2)-(X) over tilde (2)A(1) conical intersection. The strong rovibronic bands are rather isolated and organized into polyads which can be assigned by the number of bending quanta of the (A) over tilde B-2(2) state, corresponding to the transitions with the largest Franck-Condon factors. Around 9735 cm(-1), where the origin of the (A) over tilde B-2(2)-(X) over tilde (2)A(1) vibronic band system is located and up to about 11200 cm(-1), hot bands dominate the spectrum. The complexity of the spectrum increases with energy due to an increasing density of (A) over tilde B-2(2) and (X) over tilde (2)A(1) vibrational levels, The rotational structure is dense and irregular as already observed for higher bands.
Keywords:JET-COOLED NO2;VISIBLE EXCITATION SPECTRUM;ELECTRONIC-STRUCTURE;ABSORPTION-SPECTRUM;VIBRATIONAL LEVELS;NITROGEN-DIOXIDE;AB-INITIO;FLUORESCENCE;STATES;SET