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TAKASHI IMAJO, DONBBING WANG, KEIICHI TANAKA AND TAKEHIKO TANAKA, Department of Chemistry, Faculty of Science, Kyushu University 33, Hakozaki, Higashi ku, Fukuoka 812-8581, Japan.

High resolution UV emission spectrum of the 410~nm band of the TiCl radical was measured by Fourier transform spectrometer (Bruker IFS120HR) with the resolution of 0.04~cm^-1. This band was assigned as the electronic transition of ² - ² band of the TiCl radical by Phillips and Davis [1], but recent study of ZrCl[2] suggested that this band might be ⁴\Gamma - X ⁴ or ⁴ - X ⁴ band.

In the present work a new electronic assignment of ⁴ \Gamma - X ⁴ was proposed. The vibrational assignments were made for each subbands. The vibrational bands of (0-0), (1-1), (2-2), (3-3), and (4-4) were assigned for the subbands of ⁴\Gamma_5/2 - ⁴_3/2 and ⁴\Gamma_7/2 - ⁴_5/2. For the subband of ⁴\Gamma_9/2 - ⁴_7/2, the (0-0), (1-1) and (2-2) bands were assigned, but for the ⁴\Gamma_11/2 - ⁴_9/2 subband, only (0-0) band was assigned. Rotational analysis were done for ⁴\Gamma_5/2 - ⁴_3/2 and ⁴\Gamma_7/2 - ⁴_5/2 subbands. The band origins, rotational constants, and centrifugal distortion constants were determined by the least square method. The rotational constants were consistent with those reported by Ram and Bernath [3] within the experimental error. >From the line intensities of P- and R- branches, \Lambda was derived to be +1, and therefore upper state was determined to be ⁴\Gamma. Further measurements and analysis for the subbands of ⁴\Gamma_9/2 - ⁴_7/2 and ⁴\Gamma_11/2 - ⁴_9/2 should be needed to confirm the present electronic assignment definitely.

\noindent , 163-172 (1989).
\noindent 2. R. S. Ram and P. F. Bernath, J. Mol. Spectrosc. 186, 335-348 (1997).
\noindent 3. R. S. Ram and P. F. Bernath, J. Mol. Spectrosc. 186, 113-130 (1997).