Ionization Potentials of Some Organic Molecules. V. Heterocyclic Compounds Containing Nitrogen

First ionization potentials of the following substances were determined by a modified critical slope method. Pyridazine 9.86±0.05, pyrimidine 9.91±0.05, pyrazine 10.01±0.02, s-triazine 10.07±0.05, 2,3-lutidine 9.68±0.02, 2,4-lutidine 9.43±0.02, and 2,6-lutidine 9.57±0.02 eV. Interpretations of the results are given from the view-point that the ionization potentials of these compounds are largely determined by the non-bonding electrons at the N atom.