π-π* Absorption Spectrum of Pyridine-D 5

The absorption spectrum of π–π* system of pyridine-D 5 molecule has been measured in the range 33790–36990 cm −1 , on the Hilger large quartz spectrograph. A large number of sharp bands have been measured and analyzed in terms of ground and excited state frequencies which have been compared with the corresponding frequencies of pyridine-H 5 molecule.