Transients in Thermal Isomerization of Cyclobutene by the Variable Encounter Method. Vibrational Energy Transfer and Relaxation at Lower Temperatures

Article abstract of DOI:10.1021/j150605a026

Vibrational energy transfer and relaxation in the thermal isomerization of cyclobutene to 1,3-butadiene has been studied over the temperature range 429-778 K by using the variable encounter method (VEM).Reactors characterized by various mean numbers of collision, m, per encounter of substrate molecule with the reactor (m = 2.6, 5.9, 8.5, and 27.2) were used.Strong collider behavior in collisions of substrate with a seasoned fused quartz wall was observed at lower temperatures (below 450 K) as evidenced by the coincidence of values of the probability of reaction per collision, P_c(m), obtained in VEM reactors having different m values.The average energy transferred to the wall per deactivating collision, < ΔE'> = 2150 cm ^-1 at 764 K to > 6000 cm^-1 at 460 K.Various forms of models for the probability of energy transfer in down transitions were applied to data.