Jet-Cooled Optical Spectroscopy of FeN between 16 300 and 21 600 cm−1

Abstract

We report the first gas-phase spectroscopic study of iron mononitride (FeN). FeN molecules were generated by the reaction of laser-ablated Fe atoms with NH3 under supersonic jet-cooled conditions. Laser-induced fluorescence excitation spectra were measured between 16 300 and 21 600 cm−1, and rotational analyses have been performed for about 25 vibronic bands. The Ω value of the ground state has been determined to be 52, which could be the spin–orbit component of 2Δ (… 1δ39ς2) or 4Π (… 1δ39ς14π1). The excited states in the visible absorption region show very complicated rovibronic structures due to heavy perturbations. Excited state lifetimes, 56Fe14N/56Fe15N isotope shifts, and dispersed fluorescence spectra were measured for the majority of the bands, which were classified into the five Ω = 52–XΩ = 52 band systems.