Near Ultraviolet Absorption Spectrum of Pyridine-d5 Vapor

The near ultraviolet absorption spectrum of pyridine-d5 vapor due to n–π* transition was measured and analyzed. The origin is at 34951 cm−1 and higher than that of pyridine-h5 by 182 cm−1. The ground-state frequencies 582 and 1019 cm−1 and their counterparts of 511 and 953 cm−1 in the upper state dominate the progressions in the spectrum. Besides the above frequencies, several active frequencies were obtained.