Optical-optical double resonance spectroscopy of jet-cooled TiO. New 3f and 3P states near 4 eV

Abstract

Laser excitation spectra of TiO have been recorded in the 30 500–34 500 cm−1energy region using the technique of optical–optical double resonance. Twenty3Φ and 243Π excited vibrational levels have been observed in experiments that use theA3Φ andB3Π electronic states as intermediates. The new levels can be assigned to four electronic states, here labeledG3Φ,H3Φ,I3Π, andJ3Π. All the excited states are found to be perturbed to some degree; estimates of the upper state constants have been obtained from least-squares fitting of the data. Laser-induced fluorescence to a new low-lying electronic state of TiO has been observed, following excitation to theI3Π andJ3Π states; this state lies 12 284 ± 5 cm−1above theX3Δ1,J= 1 ground rotational level of the molecule and is believed to be the hitherto unobserved δ2D3Σ−state.