Abstract: Quasiclassical trajectory calculations (QCT) of the energy transfer between highly vibrationally excited pyrazine (C₄N₂H₄) and N₂, O₂, NH₃, and ground state C₄N₂H₄ were performed respectively. The calculations show when colliding with N₂ and O₂ the vibrational energy of C₄N₂H₄ transferred mainly to the vibrational contributions of N₂ and O₂, and they are V-V energy transfers. Colliding with NH₃, the vibrational energy of C₄N₂H₄ transferred mainly to the rotational contributions of NH₃, and it is V-R energy transfer. Colliding with ground state C₄N₂H₄ the energy transferred mainly to the vibrational and rotational contributions, and it is V-V(R) energy transfer. Comparing with the collision energy transfers between highly vibrationally excited C₄N₂H₄, C₆F₆, C₆H₆ and their own ground state molecules, we found that V-V energy transfer is easier if the molecule has higher symmetry.

Key words: Pyrazine, Highly vibrationally excited state, Collisional energy transfer, QCT calculation, Energy transfer mechanism