Ionization Energy and Thermochemistry of CF2Cl2 Determined from Threshold Photoelectron Spectroscopy

Abstract In this work, we performed a joint study of threshold photoelectron spectroscopy and density functional calculations on photoionization of CF2Cl2. Using the optimized geometries and vibrational frequencies of the CF2Cl2 neutral and cation in ground state at the ωB97XD/cc-pVTZ level, the Franck-Condon simulation was performed for the X2B2 band. Based on the great agreements between the experimental and simulated spectra, the observed vibrational progressions of the CF2Cl2(X1A1) → CF2Cl2+(X2B2) transition are well assigned, leading to a corrected adiabatic ionization energy of 11.565±0.010 eV. The enthalpies of formation and C-Cl bond energies of CF2Cl2 neutral and cation are then calculated, respectively.