OBSERVATION OF NEW BANDS IN THE A(1)PI(U)-X-1-SIGMA(-INDUCED FLUORESCENCE-SPECTRUM OF C-3()(G) LASER)

We report on over 100 new bands of two vibronic types Pi(u)-Sigma(g)() and Pi(g)-Sigma(u)(+) in the A(1) Pi(u)-X-1 Sigma(g)(+) laser induce d fluorescence spectrum of C-3 in the wavelength range 386-463 nm. A f ast electric discharge in the expansion region of a supersonic jet of CO produces rotationally cold but highly vibrationally excited C-3, al though the low frequency bending mode appears to be fully quenched. Th e vibronic symmetries of the upper and lower states involved in the tr ansitions are in general unambiguously assigned on the basis of the ro tational assignment but the apparent lack of ordered vibrational struc ture in the Pi(g)-Sigma(u)(+) type transitions makes vibrational assig nments for many of these bands ambiguous. Self consistent preliminary assignments for about 30 of the Pi(g)-Sigma(u)(+) bands allows new vib rational levels in the A state to be characterized. (C) 1997 Academic Press.