Rate of Vibrational Energy Transfer between Gas Molecules

RATE OF VIBRATIONAL ENERGY TRANSFER BETWEEN GAS MOLECULES 

The transfer of energy in collisions between molecules with several degrees of freedom is highly efficient, reactions of such molecules have a rate almost equal to that predicted by transition-state theory. The efficiency for energy transfer between atoms and molecules from translational to vibratioml energy decreases with increasing collision time and is most efficient for molecules with a small mass. 

The previous sections demonstrated that reaction rates may be limited by intermolecular energy transfer at low pressure. As a consequence, transition-state theory overestimates the rate constant, and the appropriate expression for the rate constant should contain energy-transfer parameters and non-equilibrium factors. 

TABLE 5.1. Energy Transfer in Various Unimolecular Reaction Systems in a Surrounding Medium (the Bath Gas)  

AE (kJ/mol) for energy transfer in various unimolecular reaction systems with bath gases M 

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