Dissociation energy of the PdO molecule

Mass spectrometric studies of the gaseous equilibrium Pd+O ⇌ PdO yield the dissociation energy D0o(PdO)=56±3 kcal mol−1. This new value is significantly lower than one recommended in the most recent review, D0o(PdO)=90±20 kcal mol−1, where an earlier value near 55 kcal mol−1 was rejected because of higher values ranging from 90 to 98 kcal mol−1 for neighboring metal monoxides. It is shown that the lower value reported here is consistent with the unique closed-shell structure of the Pd atom.