Vibrational energy flow into a reactive coordinate: A theoretical prototype for a chemical system

A realistic model is developed to illustrate vibrational energy flow into a reactive coordinate. The isomerization of C≡N–H to H–C≡N is enhanced nonstatistically through overtone excitations of the H–N bond. The mechanism determined for this theoretical model is dominated by resonant energy transfer from the anharmonically suppressed H–N mode into a combination of the C≡N plus the bending reaction coordinate. Implications of this classical prototype to mode specific chemistry, in particular the prediction of possible quantum tunnelling enhancement, are discussed in terms of experimentally observable systems.