Near infrared laser spectroscopy of ScBr: The e3Δ – a3Δ and d3Φ – a3Δ systems

Abstract Electronic transition spectrum of scandium monobromide (ScBr) has been studied between 787 and 854 nm using laser vaporization/reaction free jet expansion and laser induced fluorescence spectroscopy. ScBr molecule was produced by reacting Sc atom with ethyl bromide. Spectra of nine vibrational bands of the e 3 Δ – a 3 Δ and the d 3 Φ – a 3 Δ systems were obtained and analyzed. Transition lines of both Sc 79 Br and Sc 81 Br isotopes were observed. A least-squares fit of the measured line positions yielded accurate molecular constants for the v  = 0 and 1 levels of the d 3 Φ state and the v  = 0–2 levels of both e 3 Δ and a 3 Δ states. The bond length of the v  = 0 level, r o , of the a 3 Δ state has been determined to be 2.4533 A. A molecular orbital energy level diagram has been used to examine the electronic configurations giving rise to the observed electronic states.