ELECTRONIC ABSORPTION-SPECTRA OF LINEAR CARBON CHAINS IN NEON MATRICES .1. C-6(-), C-6, AND C6H

Electronic absorption spectra of linear C6, 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 C6 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 O00 transitions of C6: 2Πg←X2Πu, C6: 3Σu-←X3Σ 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. © 1995 American Institute of Physics.