Raman Spectrum of Nitrous Oxide

Abstract

WE have photographed the Raman spectrum of nitrous oxide with a four-prism glass spectrograph having a camera lens of diameter 5 cm. and focal length 70 cm. The gas was at a pressure of 30 atmospheres and was illuminated with four 32 cm. long mercury lamps, container and lamps being surrounded by a reflector of suitable shape. The exposure time was 14 days, the spectrograph being, of course, enclosed in a thermostat. Average values of the frequency shifts obtained are listed in the first column of the accompanying table. In the third column are stated the transitions to which the Raman lines are ascribed, the quantum numbers V₁, V₂, V₃, and l, introduced by Dennison,¹ being used to designate the vibrational states of the molecule. The fourth column, finally, gives the values of the frequency shifts as computed from the recent infra-red absorption measurements of Plyler and Barker.²