Electronic absorption spectra of linear carbon chains in neon matrices. I. C−6, C6, and C6H

Abstract

Electronic absorption spectra of linear C−6, C6, and C6H have been identified in neon matrices at 5 K. The species were produced by codepositing mass selected cations and anions with neon. The ions were generated in a hot cathode discharge source using diacetylene. The spectra of C−6 and C6 could also be observed using a pure carbon anion source or laser vaporization of graphite. The assignment is based on the mass selection, experimental and spectroscopic evidence, leading to the location of the 000 transitions of C−6: 2Πg←X 2Πu, C6: 3Σ−u←X 3Σ−g, and C6H: 2Π←X 2Π at 16 458, 19 558, and 18 854 cm−1, respectively. The frequencies of the symmetric carbon stretching vibrations have been obtained for these species in their excited electronic states.