The geometry and inversion-internal rotation potential function of methylamine

Abstract

The geometry and the inversion-internal rotation potential function of methylamine, CH3NH2, have been determined from the rotational spectrum in the ground vibrational state, and from the PQ and RQ branches in the first excited states of inversion and of internal rotation. The rotation-vibration energy levels have been calculated directly from the structure and from the potential function using a semirigid inversion-internal rotation-rotation Hamiltonian. It is hoped that this approach will make it possible to assign the rotational structure of the infrared internal rotation and inversion bands.