Reaction Kinetics of a Selected Number of Elementary Processes Involved in the Thermal Decomposition of 9-Methylphenanthrene Using Density Functional Theory

Abstract

With the use of general transition state theory and density functional theory, six reference reactions that are thought to play an essential role in the thermal cracking process of 9-methylphenanthrene have been studied. At the uB3LYP/6-31G(d,p) level, the transition state structures could be located on the 0 K potential energy surface for the three propagation reactions which induce no net creation/annihilation of radicals, and the calculated activation energies and preexponential frequency factor generally correspond well to experimental values. The transition states for two termination reactions were determined by replacement of a phenanthrenic by a phenylic aromatic moiety; it followed that such model reactions represent well systems with larger aromatic units. Only for the initiation reaction the transition state could not be located; in this case the activation energy was approximated by the change in overall enthalpy.