The high-resolution He 584Aophotoelectron spectra of heptafluoroquinoline and heptafluoroisoquinoline are compared with those of the parent compounds. Shifts in π ionisation potentials, due to the fluorine substitution, can be described with an inductive and a combined inductive-conjugative Hu¨ckel model.
van den Ham, D. M. W., & van der Meer, D. (1972). Perfluoro effect in the photoelectron spectra of quinoline and isoquinoline. Chemical physics letters, 15(4), 549-552. https://doi.org/10.1016/0009-2614(72)80368-3