Near-infrared laser spectroscopy of TiS: The b¹II-X³Δ transition

Laser-induced fluorescence spectrum of TiS in the 769-863 nm region has been recorded and analyzed. The TiS molecule was produced using the technique of laser vaporization/reaction with supersonic cooling. Twenty-one weak subbands have been assigned as being due to b1II-X3, B3II0-X3Δ1, and C3Δ-X3Δ transitions. Strong evidence shows that the b1II state is responsible for perturbing the v = 0, 1, and 2 levels of the C3Δ1subband. The molecular constants of the b1II state have been determined as follows: Te= 10 589.47 cm-1, ωe= 542.14 cm-1, ωexe= 3.16 cm-1, Be= 0.19568 cm-1, and αe= 0.00085 cm-1. The spin-orbit interaction between the b1II (v = 2 and 3) and C3Δ (v = 1 and 2) levels is discussed in terms of configuration interaction occurring between the b1II from the 11σ15π1configuration and the1II from the 5π11δ1configuration, and the C3Δ state from 12σ11δ1configuration,