The C–N stretching band of methylamine

For the first time the C–N stretching band of methylamine has been assigned in a high resolution spectrum in the region from 960 to 1200 cm⁻¹. Over 3500 transitions with a resolution of 0.001 cm⁻¹ for K from 0 to 12 have been assigned. A global fit has been made and the band center was determined at 1044.8134(33) cm⁻¹. Several branches of the C–N band are strongly perturbed through Fermi and Coriolis type resonances. The sources of the perturbations have been identified – the fourth torsional state 4ν₁₅ and the combination state ν₉ + ν₁₅. An attempt to fit the observed transitions to a single state model based on the group theoretical formalism of Ohashi and Hougen 1] resulted in the standard deviation of 0.04 cm⁻¹.