Knowledge Bank

The $d3\Pi g-c3\Sigma u+$ band system of C$2$ was observed in a discharge flow cell by laser induced fluorescence spectroscopy. Although the observation of the band system has been reported for the jet-cooled C$2$ molecule, , J.~Chem.~Phys. 127, 214303 (2007).} transitions involving higher rotational levels were observed in the present study. Improved molecular constants for several vibrational levels of the $c3\Sigma u+$ state will be presented. Furthermore, the bands with $v\prime \prime =5,6,7$ were newly observed in a discharged supersonic jet, of which molecular constants were determined for the first time.