Photoelectron Spectroscopy of CCO- and HCCO-

Article abstract of DOI:10.1021/j150642a010

Using negative ion photoelectron spectroscopy we have measured the electron affinities (EA) of CCO and HCCO.We find EA(CCO) = 1.848 +/- 0.027 eV and EA(HCCO) = 2.350 +/- 0.020 eV.In separate experiments with a flowing afterglow device, we have determined the gas-phase acidity of ketene and report it as ΔH⁰_acid(CH2CO) = 365 +/- 2 kcal/mol.These data afford the ketene bond dissociation energy, DH⁰₂₉₈(H-CHCO) = 105.9 +/- 2.1 kcal/mol, and the heats of formation: ΔH_f⁰₂₉₈(HCCO) = 42.4 +/- 2.1 kcal/mol and ΔH_f⁰₂₉₈(HCCO^-) = -13.3 +/- 2.1 kcal/mol.