Knowledge Bank

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 $\nu 1=1549cm-1,\nu 2=567cm-1$ and $\nu 3=859cm-1$. 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.