Knowledge Bank

Doppler-limited tunable-diode-laser spectra of the stretching fundamental $v3$ of $\mathrm{<mrow\; data-mjx-texclass="ORD">28</mrow>}SiF4$ at $1031cm-1$ have been analyzed and the spectroscopic constants of this band determined. Explicit identifications have been made for transitions near the $9.5\mu m$ lines of the $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C16O2$ laser and its various isotopes; several dozen such transitions have been observed and their frequencies precisely measured in sub-Doppler saturation spectra obtained with a waveguide $CO2$ laser. The closest coincidence is R(53) $F19$ of $\mathrm{<mrow\; data-mjx-texclass="ORD">28</mrow>}SiF4$, at $-1.391$ MHz from $\mathrm{<mrow\; data-mjx-texclass="ORD">12</mrow>}C16O2$ P(30). Implications for isotope enrichment experiments will be discussed.