Knowledge Bank

In a previous $paper,1$ Lewis-Bevan et al. outlined the assignment and analysis of the two stronger fundamentals of $CH2DF$ in the 9-11 $\mu m$ region, $v5$ and $v6$, together with weaker $v9$ fundamental. At that time it was suggested that the inclusion of $v8$ would aid in the analysis of the data. In this paper we report the progress of the analysis of the four fundamentals. The data were re-recorded using both a high resolution BOMEM DA3.002 FT-IR instrument and a tunable diode laser. The diode laser was used to improve the resolution, sensitivity, and signal to noise of the very weak $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$Q-branches of the $v9$ fundamental, first observed in the FT-IR spectrum. The analysis has been extended to include the strong $v8$ fundamental. Molecular constants will be reported for the ground state and all four excited vibrational states of the molecule. $\mathrm{<mrow\; data-mjx-texclass="ORD">1</mrow>}$W. Lewis-Bevan, D.F. Eggers, W.D. Stork and M.C.L. Gerry, Paper MF7 at the Forty-Fifth Symposium on Molecular Spectroscopy, June 11-15, 1990.