Vibration-rotation bands of nitrous oxide

Abstract

The infra-red absorption of nitrous oxide gas near 4$\cdot $5 $\mu $ has been re-investigated using high resolving power. The rotational fine structure has been split up and shown to involve two vibrational transitions, one due to absorption of a fundamental from the ground state, and the other to a $\pi \rightarrow \pi $ transition from an excited vibrational level. The transitions have been analyzed theoretically and rotational constants obtained. The results serve to emphasize the importance of using more precise wave-length standards for infra-red measurements than have been used hitherto, if the rotational constants are to be obtained with accuracy comparable to that achieved by microwave measurements. Excellent agreement with the latter has now been found.