CHEMICAL REACTION JET SPECTROSCOPY OF THE $\tilde{A}^{1}A" - \tilde{X}^{1}A'$ 430 NM BAND SYSTEM OF HSiF

Abstract

Jet-cooled LIF spectra of the 430 nm band system of HSiF were obtained by the reaction of molecular fluorine with silane in the throat of a continuous supersonic jet. Vibrational analysis of the spectrum gave upper state harmonic vibrational frequencies of $\nu_{1} = 1549 cm^{-1}, \nu_{2} = 567 cm^{-1}$ and $\nu_{3} = 859 cm^{-1}$. Seven bands were recorded at high resolution and rotationally analyzed, providing excited state rotational constants. The upper state vibrational and rotational bending levels were fitted to a semi-rigid bender model to obtain the equilibrium geometry and barrier to linearity. These will be discussed in comparison with recent ab initio calculations of the excited state properties.