Knowledge Bank

Isotopically enriched carbon monoxide (88% $\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C\mathrm{<mrow\; data-mjx-texclass="ORD">16</mrow>}O,12\%\mathrm{<mrow\; data-mjx-texclass="ORD">13</mrow>}C\mathrm{<mrow\; data-mjx-texclass="ORD">18</mrow>}O$) dissolved in liquid argon was optically pumped to the $v=1$ level by a cw CO laser. This energy is redistributed by collisional up-pumping to higher vibrational levels. Fluorescence from vibrational levels up to $u=37$ of the heavier isotope was observed from the steady-state distribution. A discontinuity in the fluorescence at $v=28$ is observed which happens to be isoenergetic with the excited $a3\Pi$ electronic state of CO. The $X1\Sigma \to a3\Pi$ intersystem crossing behavior and reactions which form isotopic carbon dioxide will be discussed.