Knowledge Bank

Tunable diode laser spectra are obtained of several Q branches in the $\nu 2+\nu 7$ sum bands of $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C316O2 at 820-850cm-1$. Molecular constants are determined for the ground state transition at $819.69cm-1$ and for the first two ``hot” bands, which are shifted to higher frequency. The $\ell$ -doubling constant in the $\nu 71$ state was found to be 4.16 $\pm$ 0.06 $\pm 10-4cm-1$, and that in the $\nu 2+\nu 7$ state 2.96 $\pm$ 0.04 $\times 10-4cm-1$.