Heat of formation of the CF 2++ dication: a theoretical estimate

Abstract

Relative energies and ionization potentials of neutral and ionic fragments of CF 4 were calculated using the coupled cluster single double (triple)/correlation consistent triple zeta basis set ab initio method. The individual values were compared with available experimental and theoretical data to assess the accuracy of this approach for these particular systems. In addition, reaction enthalpies for possible fragmentation reactions were calculated. Maximum errors found were in the order of 5 kcal/mol (0.2 eV). The estimation of the heat of formation of the CF 2 ++ dication, derived from the calculations based on four different reactions, is 687 ± 5 kcal/mol (29.8 ± 0.2 eV). This value is considerably smaller than the one which follows from the appearance potential measurements (732 ± 7 kcal/mol).