The vacuum-ultraviolet photoelectron spectra of fluoropyridines

Abstract

The high-resolution photoelectron spectra of pyridine, 2-fluoropyridine, 3-fluoropyridine, 2,4-difluoropyridine, 2,6-difluoropyridine, 2,4,6-trifluoropyridine, and pentafluoropyridine have been measured. The shifts of the first four bands across the series have been correlated by invoking a first-order inductive perturbation by fluorine. From this correlation the order of the levels in pyridine has been deduced as π₃ > n > π₂(a₂ > 11a₁ > 2b₁).