Infrared laser absorption spectroscopy of the SiH+3 cation

Abstract

Many vibration–rotation components of the ν₂ fundamental of the SiH⁺₃ cation have been measured using diode laser velocity modulation spectroscopy. By comparing the intensities of these components with their nuclear statistical weights, the ion is shown to be planar (D_3h). The position of the ν₂ band center is 838.0674(7) cm⁻¹ and the ground state rotational constant is B₀=5.2153(1) cm⁻¹, r₀=0.1462 nm. These results are compared with ab initio calculations.