Ionization potentials of dipyridyls and diquinolyls

The ionization potentials of a number of isomeric dipyridyls and diquinolyls were determined. The differences in their values make it possible to establish the site of fusion of the rings in the 2,2, 3,3, and 4,4 positions of the system. The absence of an appearance potential for the fragment ion, the existence of which is due to cleavage of the interannular bond in the doubled hetaryl compounds, constitutes evidence for its double-bond character.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 812–814, June, 1976.