15min:

C. AMIOT, P. LUC AND R. VETTER, Laboratoire Aimé Cotton (CNRS UPR3321), Campus d'Orsay, Bâtiment 505, 91405 Orsay, France.

We have studied the yellow-orange absorption spectrum of the TiO molecule by use of a Doppler-free spectroscopy experiment in which a cw tunable laser beam crosses an effusive beam of titanium monoxide. Thousands of wavenumbers belonging to the B³ - X³(1-0) and c¹ - a¹(0-0) bands have been measured to an accuracy of 10^-3 cm^-1 and interpreted in terms of molecular constants. For the first band, analysis of fine structure and \Lambda-doubling shows that the electronic structure of the B³ state must be revisited. For the second band, electronic interactions with distant vibrational levels of the c³ state must be considered to assign high rotational levels. Analysis of the spectra due to the five isotopes of titanium is on the tracks.