The energy levels of the CH3 asymmetric bending vibrations of toluene

Abstract

The energy levels of the CH₃ asymmetric bending vibrations of toluene were calculated by the use of a finite element method for the two dimensional vibrational Schrödinger equation on the basis of a C_2v symmetry of the molecule. The totally symmetric CH₃ torsion was only considered and some boundary conditions were used for the CH₃ asymmetric bending vibrations. The splittings of the energy levels were examined in relation to the interaction potential V₂ or V₆′ with the CH₃ asymmetric bending and the CH₃ torsional coordinates. The ir spectrum was observed in the region of those vibrations at room temperature and the Raman experiments at about −140 °C. The observed bands were assigned by comparing them with the calculated levels.