The vapor-phase Raman spectra and the ring-puckering vibration of some deuterated analogs of trimethylene oxide

The ring-puckering vibration has been observed in the Raman spectra of the vapor phase of several deuterated species of trimethylene oxide (α - d₂, β - d₂, α, α′ - d₄, and d₆). Only Δv = 2 transitions have a measurable Raman intensity. The line positions agree with infrared values to better than 0.5 cm⁻¹ in most cases and better than 1 cm⁻¹ in all cases. For all molecules the interpretation of the spectra is consistent with an essentially planar configuration having only a small barrier to inversion.