Thermal dimerization of 1,3-cyclohexadiene in the gas phase

Abstract

The thermal dimerizations of 1,3-cyclohexadiene(Chd), 2 Chd→exo-dicyclohexadiene (D3)k_D3(a) and 2 Chd→endo-dicyclohexadiene (D4)k_D4(b) have been studied between 471.1 and 638.5 K at pressures ranging from 25 to 630 Torr. These reactions are second order and the rates are unaffected by the surface-to-volume ratio or by the presence of added propene. The rate constants are given by log₁₀k_D3(1.mol^–1s^–1)=–(25 100 ± 500)/4.576 T+(5.97 ± 0.25), and log₁₀k_D4(1.mol^–1s^–1)=–(24 300 ± 500)/4.576 T+(6.08±0.25).