Laser-induced fluorescence spectroscopic study of the [21.2]0+–X0+ and [22.2]0+–X0+ electronic transitions of tungsten monoxide

Abstract

The laser-induced fluorescence (LIF) excitation spectra of jet-cooled WO molecule have been investigated in the range of 21,000–23,200 cm−1, and two electronic band systems have been observed for the first time and labeled as the [21.2]0+–X0+ and [22.2]0+–X0+ transitions. The vibrational and rotational constants of these two excited electronic states have been derived by rotational analysis of the spectra. The tungsten isotopic structures of these two excited states are clearly resolved, and the analysis of LIF spectra reveals that the isotopic shifts are due to the strong interstate perturbations between different vibronic states. Based on the ab initio calculation results by Ram et al., the primarily attributed configuration of these two newly identified states was discussed. In addition, the lifetimes of the observed vibronic states were measured under the collision-free condition.