Photoelectron spectra of some fluorine substituted diazanaphthalenes

The high resolution He 584 Å photoelectron spectra of fluorine substituted 1,2-diaza-, 1,3-diaza-, 1,4-diaza- and 2,3-diaza-naphthalene are presented. By means of fluorine substitution the analysis of the photoelectron spectra of the parent compounds can be made more definite. Unexpected shifts of the nitrogen “lone-pair” bands can be explained within the through-space and through-bond interaction model. From this explanation one can deduce that fluorine substitution can give experimental evidence about the symmetry character of the “lone-pair” molecular orbitals.