Knowledge Bank

The dispersed laser-induced technique has been applied for the first time to metallic molecular ions. The $TiCl+$ and $TiF+$ ions were produced by a high-voltage discharge in hbelium with traces of $TiCl4$ or $TiF4$, respectively. A c.w. dye-laser and a grating specytrometre were used a record low-resolution spectra of these species in the visible region. This led to the the observation of new low-lying electronic states of these ions: the $C3\Pi (\sim 1535cm-1)$ state of $TiCl+$, the $B3\Delta (\sim 2040cm-1)$ and $C3\Pi (\sim 2200cm-1)$ states of $TiF+$. The identification of these new states contributes to a better characterization of the first 3000 $cm-1$ of the energy level diagram of these molecules. The experimental position of the $C^{3}\Pi $ state of $TiCl+$ is in good agreement with theoretical predictions given by a Ligend Field Theory $model.a$ We have extended these calculations of the $TiF+$ isovalent ion, taking advantage of the new experimental data. Both experimental and theoretical new results presented here are expected to help future high-resolution investigations on these species. C. Focsa, M. Bencheikh, and L. G. M. Petterson, J. Phys. B. At. Mol. Opt. Phys. 31, 2857-2869 (1998). $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$ Present address: Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada N2L 3GT1.