Knowledge Bank

Electronic spectra of $TiCl$ have been studies for years by various spectroscopic methods. However, it is still not clear whether the ground state of $TiCl$ is $\mathrm{<mrow\; data-mjx-texclass="ORD">4</mrow>}\Phi r$ which is assumed to be the case by the analogy of TiH and the results of ab initio calculations. In this study, we have detected pure rotational spectra of $TiCl$ for four spin components by using a submillimeter-wave spectrometer with a combination of frequency and discharge modulations a Ibaraki University. $TiCl$ is generated in a DC glow discharge of a gas mixture of $TiCl4(\sim 1mTorr)$ and Ar buffer ($\sim 80$ mTorr). Discharge current is 40 mA, and mainly the 440 GHz region is surveyed. We have obtained effective spectroscopic constants for all the spin-components for v = 0 that are consistent with the previous FT results. Our analysis will provide very accurate structural information on the ground electronic state of this radical.