Photoelectron spectra of dicarbon(1-) and ethynyl(1-)

摘要: The photoelectron spectra of C{sub 2}{sup {minus}} and 2}H{sup have been measured at a photon energy 3.531 eV. electron affinities dicarbon, EA(C{sub 2}) = 3.269 {plus minus} 0.006 eV, ethynyl radical, 2}H) 2.969 are determined. dissociation dicarbon anion, D{sub 0}(C{sub {minus}}) 187.2 2.5 kcal mol{sup {minus}1}, is derived from the experimental 2} C literature value for neutral 141.0 {minus}1}. CC stretch fundamental CCH bending vibrational levels up to v 3 observed in 2}H(X{sup 2}{Sigma}{sup +}). frequencies {minus}}(X{sup 1}{Sigma}{sup +}) 1,800 20 cm{sup {minus}1} (CC stretch) 505 (CCH bend). spectrum exhibits strong non-Franck-Condon transitions, induced by vibronic coupling, odd bend.