Far-Infrared Spectra and Structure of Small Ring Compounds. VIII. Pseudorotation in 1,3-Dioxolane

The infrared and Raman spectra of 1,3‐dioxolane have been examined from 800–33 cm⁻¹. A series of $Q$ branches in the spectral region of 33–100 cm⁻¹ has been treated on the basis of pseudorotation. A series of $Q$ branches was also observed in the 200–400 cm⁻¹ region and has been assigned to hot band transitions arising from excited states of the pseudorotational levels. The mid‐infrared also shows considerable structure, but the complexity due to overlapping fundamentals precludes their unique assignment. The spectroscopically derived parameter ${\mathrm{mq}}_0^2$ was found to be 7.4 × 10⁻⁴⁰g·cm² which agrees well with the value found for the corresponding quantity for the tetrahydrofuran molecule.