Fourier transform infrared emission spectroscopy of the C4Δ-X4Φ, G4Φ-X4Φ, and G4Φ-C4Δ systems of TiCl

The emission spectrum of TiCl has been investigated in the 3000-12 000 cm(-1) region at high resolution using a Fourier transform spectrometer. The bands were excited in a microwave discharge through a flowing mixture of TiCl4 and helium. The observed bands have been classified into three electronic transitions, C-4 Delta-X-4 Phi, G(4) Phi-X-4 Phi, and G(4) Phi-C-4 Delta. In the 3000-3500 cm(-1) region, four bands with R heads at 3368.7, 3331.8, 3291.9, and 3243.4 cm(-1) have been assigned as the 0-0 bands of the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands, respectively, of the C-4 Delta-X-4 Phi transition. To higher wavenumbers, four transitions with 0-0 R heads at 10 930.7, 10 921.3, 10 906.5, and 10 886.9 cm(-1) have been assigned as the 3/2-3/2, 5/2-5/2, 7/2-7/2, and 9/2-9/2 subbands, respectively, of the G(4) Phi-X-4 Phi system of TiCl. Four additional bands with 0-0 R heads at 7568.8, 7596.4, 7622.2, and 7651.7 cm(-1) have been identified as the 1/2-3/2, 3/2-5/2, 5/2-7/2, and 7/2-9/2 subbands of the G(4) Phi-C-4 Delta transition, respectively. A rotational analysis of a number of vibrational bands of these transitions has been obtained and molecular constants have been extracted. The lowest 4 Phi state has been assigned as the ground state of TiCl, by analogy with our recent work on TiF (R. S. Ram and P. F. Bernath, J. Mol. Spectrosc., in press). The correspondence between the electronic states of TiCl, TiF, TiH, and Ti+ is also discussed. (C) 1997 Academic Press.