HIGH RESOLUTION FOURIER TRANSFORM UV EMISSION SPECTROSCOPY OF THE 410 NM BAND OF THE TiCl RADICAL

Abstract

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 $^{2}\Phi-^{2}\Delta$ band of the TiCl radical by Phillips and Davis [1], but recent study of ZrCl[2] suggested that this band might be $^{4}\Gamma-X^{4}\Phi$ or $^{4}\Phi-X^{4}\Phi$ band. In the present work a new electronic assignment of $^{4}\Gamma-X^{4}\Phi$ 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 $^{4}\Gamma_{5/2}-^{4}\Phi_{3/2}$ and $^{4}\Gamma_{7/2}-^{4}\Phi_{5/2}$. For the subband of $^{4}\Gamma_{9/2}-^{4}\Phi_{7/2}$, the (0-0), (1-1) and (2-2) bands were assigned, but for the $^{4}\Gamma_{11/2}-^{4}\Phi_{9/2}$ subband, only (0-0) band was assigned. Rotational analysis were done for $^{4}\Gamma_{5/2}-^{4}\Phi_{3/2}$ and $^{4}\Gamma_{7/2}-^{4}\Phi_{5/2}$ 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, $\Delta \Lambda$ was derived to be +1, and therefore upper state was determined to be $^{4}\Gamma$. Further measurements and analysis for the subbands of $^{4}\Gamma_{9/2}-^{4}\Phi_{7/2}$ and $^{4}\Gamma_{11/2}-^{4}\Phi_{9/2}$ should be needed to confirm the present electronic assignment definitely.