High-resolution spectroscopy on the B²Σ⁺,ν' = 0→X²Π, ν″ =1 transition in SiCl

High-resolution laser-induced fluorescence spectra of28Si35Cl and 28Si37Cl have been observed in a molecular beam. Accurate constants describing the rotational structure in the X 2Π, ν″ = 1 as well as in the electronically excited B 2Σ+, ν' = 0 state are given. An inverted fine structure was found in the excited state with a spin-splitting constant γ = −31.15±0.19 MHz for Si35Cl and γ = −30.62 ±0.61 MHz for Si37Cl