15min:
DIRECT OBSERVATION OF THE c3 Sigmau+ STATE OF C2.

DAMIAN L. KOKKIN, NEIL J. REILLY, JENNA A. JOESTER, MASAKAZU NAKAJIMA, KLAAS NAUTA, SCOTT H. KABLE AND TIMOTHY W. SCHMIDT, School of Chemistry, University of Sydney, NSW 2006, Australia.

The d3 Pig-c3 Sigmau+ system of dicarbon was observed in a discharged supersonic jet of C2H2.\footnoteD.~L.~Kokkin et al. , J.~Chem.~Phys. \underline\textbf125, 231101 (2006). A spectral survey was carried out based on the result of high-level ab~initio calculation.\footnoteD.~L.~Kokkin et al. , J.~Chem.~Phys. \underline\textbf126, 084302 (2007). LIF excitation spectra of the band system were recorded by detecting fluorescence of the Swan system (d3 Pig-a3 Piu). Several molecular constants of the c3 Sigmau+ state were experimentally determined from the rotationally resolved spectra. Characterization of the c3 Sigmau+ state of C2 is of importance to astrophysical models of the species.