Ionization Energies, Appearance Energies, and Thermochemistry of CF2O and FCO

Article abstract of DOI:10.1021/j100014a002

With the discharge flow-photoionization mass spectrometer (DF-PIMS) coupled to the U-11 beamline at the National Synchrotron Light Source, we have measured the ionization energies of C2F4, CF2, and CF2O and appearance energy of FCO⁺ from CF2O.The PIMS results corroborate those determined by other techniques.With high-level ab initio calculations that utilize a large basis set and isogyric corrections, we have determined an ionization energy of 9.3 +/- 0.1 eV for FCO.At 298 K, the heats of formation of FCO (-152 +/- 12 kJ/mol) and FCO⁺ (745.3 +/- 9.6 kJ/mol) fH⁰₂₉₈(CF2O) = -607.9 +/- 7.1 kJ/mol> were determined and agree to within the uncertainties of other measurements but with much higher precision.We have evaluated the bond strengths D⁰₂₉₈(F-CFO) and D⁰₂₉₈(F-CO) to be 535 +/- 12 and 121 +/- 12 kJ/mol, respectively.