Spectroscopy of TiH: Rotational analysis of the 4Γ→<i>X</i> 4Φ (0,0) band at 530 nm

Abstract

Emission bands of the TiH radical in the region 18 000–20 000 cm−1 have been recorded both with grating spectrograph and Fourier transform techniques. The rotational structure of the 530 nm band, which is the strongest one of the three observed bands, has been analyzed and molecular parameters have been derived for the electronic states involved. The electronic assignment of this band is confirmed as 4Γ→X 4Φ, with a heavily perturbed upper state. The principal parameters (cm−1) of the analyzed states are X 4Φ (v=0): A=33.083(29), B=5.362 06(19), and γ=0.1823(27). 4Γ (v=0): T=18 878.10(47), A=41.54(10), B=5.7408(22), γ=−4.33(12), and λ=0.77(14). The derived first order spin–orbit parameter values of X 4Φ and 4Γ are shown to be consistent with the electronic configurations δπσ and δππ′, respectively. The local perturbations in the 4Γ state are discussed and arguments are given to suggest that the dominating perturber is of 4Φ symmetry.