CALCULATION OF VIBRATIONAL-ENERGY-TRANSFER QUANTITIES AT HIGH-TEMPERATURES - ENERGY AND TEMPERATURE-DEPENDENCE

An improved correlation between the energy-transfer quantities 〈ΔE〉all and 〈ΔE〉d has been compared to a widely used approximate expression as a function of temperature and pressure with special reference to the reported unimolecular thermal decomposition of cyclohexene. It is found that significant deviation between the two expressions can arise at high temperature (2000 K) and low pressures. Specification of the average energy level of colliding molecules is a necessary input for this correlation under some experimental conditions. The difficulty encountered in making such a specification for the falloff region is pointed out. These considerations are particularly relevant in high-temperature systems such as shock tubes, flame, and combustion. © 1990 American Chemical Society.