Momentum distributions, spin distributions, and bonding in CH3NH2 and its radical cation

The highest occupied molecular orbital and theoretical spin densities of methylamine and its cation have been examined utilizing electron momentum and electron paramagnetic resonance spectroscopies. The experimental results support the Hartree-Fock and Dyson orbital calculations for methylamine. Moreover, the spectral results indicate a hyperconjugative delocalization of the N lone pair electron of the neutral molecule onto the CH3 group. The methyl and amino groups in methylamine exhibit electron-withdrawing properties relative to H in preparing methylamine from NH3 and CH4, respectively.