Thermodynamic Investigation on the Pyrolysis of 1-Hexene

The pyrolysis of 1-hexene can act as a prototype of pyrolytic mechanism in petroleum processing. Details of C–C bond cleavage in the 1-hexene pyrolysis were investigated at the MP2/6-311++G~(**) basis set level. The equilibrium geometries and key thermodynamic parameters such as Gibbs free energies and thermal enthalpies were gained. Our theoretical results show that the entropy effect plays a significant role in dissociative processes. The dissociation of 1-hexene-4-yl radical into C_4H_6 and C_2H_5 is not an elementary reaction, but a process involving H-transfer and C–C rupture.