Quantum tunneling of hydrogen atom in dissociation of photoexcited methylamine.

The probability of hydrogen atom release, following photoexcitation of methylamine, CH(3)NH(2), is found to increase extensively as higher vibrational states on the first excited electronic state are accessed. This behavior is consistent with theoretical calculations, based on the probability of H atom tunneling through an energy barrier on the excited potential energy surface, implying that N-H bond breaking is dominated by quantum tunneling.