Knowledge Bank

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 $B3\Pi -X3\Delta (1-0)$ and $c1\Phi -a1\Delta (0-0)$ bands have been measured to an accuracy of $10-3cm-1$ and interpreted in terms of molecular constants. For the first $banda$, analysis of fine structure and A-doubling shows that the electronic structure of the $B3\Pi$ state must be revisited. For the second $bandb$, electronic interactions with distant vibrational levels of the $c3\Delta$ state must be considered to assign high rotational levels. Analysis of the spectra due to the five isotopes of titanium is on the tracks.