Proceedings of the Royal Society of London A Mathematical and Physical Sciences · 1964 · 32 citations · 0 references
Natural SciencesChemistryPhysicsMolecular PhysicsSpectroscopic AnalysisSpectroscopyInfrared SpectroscopyMolecular SpectroscopyOptical SpectroscopyVibrational SpectroscopyVibrational StructureInfrared SpectraRotational-vibrational CouplingTorsional-vibrational CouplingVibrational Absorption BandsVibrational Band StructureVibrational CouplingVibrational-rotational Coupling
Abstract The perpendicular C—H stretching band of dimethylacetylene is studied theoretically. It is shown that the doubling of the main peaks observed by Mills & Thompson (1954) is probably due to vibrational coupling between the two methyl groups. The torsional barrier is estimated to be not greater than about 10 cm-1, and it is shown how the barrier could be accurately evaluated from a somewhat better-resolved infra-red spectrum.