Electronic Absorption Spectra of C₄O^- and C₄S^- in Neon Matrixes

Abstract

The electronic spectra of the anions C4O- and C4S- have been observed by absorption spectroscopy in a neon matrix using mass selection. The symmetries of the states are determined on the basis of spectroscopic evidence and ab initio calculations. Two absorption systems of C4O- are assigned to the A2Σ+ ← X2Π and B2Π ← X2Π electronic transitions, with band origins near 875 and 442 nm, respectively. The B2Π ← X2Π system of C4S-, with the origin near 568 nm, has also been observed. After photobleaching, the 3Σ- ← X3Σ- electronic transition of C4S is observed around 447 nm.