RAMAN SPECTRA OF COMPOUNDS UNDER IVERSION MOTIONS - N-METHYLPYRROLIDINE.

Raman spectra of N-methylpyrrolidine were measured in various states and a normal vibration calculation was carried out on its conformers. Results of the measurement and calculation indicate that the Raman band of the inversion vibrational mode is caused to shift remarkably by the formation of hydrogen bond to the nitrogen atom. This phenomenon, along with the enthalpy of hydrogen bond formation obtained from measurements at various temperatures, suggests that the conformer predominant in pure liquid corresponds to one minimum in the potential for the inversion motion, which has a low potential barrier and high anharmonicity.