Analysis of the Near Ultraviolet Absorption Spectrum of Pyridine N-Oxide Vapor

The near ultraviolet absorption spectrum of pyridine N-oxide vapor was studied under a medium dispersion, and the vibrational analysis was made for the discrete band system near 3300 A. The electronic transition of this system is interpreted as an allowed A1–B2 transition arising from the excitation of a 2p nonbonding electron of the oxygen atom into the unoccupied π orbital.