The far-infrared laser magnetic resonance spectrum of the SiH radical and determination of ground state parameters

Abstract

The far-infrared laser magnetic resonance (LMR) spectrum of the SiH radical in the υ=0 level of its X 2Π state has been recorded. The signals are rather weak. The molecules were generated in the reaction between fluorine atoms and SiH4. Rotational transitions have been detected in both 2Π1/2 and 2Π3/2 spin components but no fine structure transitions between the spin components were observed. Proton hyperfine splittings were resolved on some lines. The measurements have been analyzed, subjected to a least-squares fit using an effective Hamiltonian and the appropriate molecular parameters determined. The weakness of the spectrum and the failure of attempts to power saturate favorable lines are both consistent with a small value for the electric dipole moment for SiH.