DEVELOPMENT OF TEMPERATURE-INDEPENDENT QUANTITATIVE STRUCTURE REACTIVITY RELATIONSHIPS FOR METAL-CATALYZED AND ACID-CATALYZED REACTIONS/

Hydrocracking of a mixture of naphthalene and phenanthrene in the temp erature interval 300-370 degrees C offered information on the temperat ure dependence of rate, equilibrium and adsorption constants. The numb er of parameters needed to describe phenanthrene and naphthalene hydro cracking kinetics was then reduced by the development of temperature-i ndependent quantitative structure/reactivity relationships (QSRRs) for the activation and reaction enthalpies and entropies. Activation ener gies for isomerization and ring opening reactions were correlated with the heat of formation of the intermediate carbocation. Activation ene rgies for hydrogenation were correlated with the standard reaction ent halpy. The principle of compensation was successfully used to relate e ntropic quantities to enthalpic quantities. The existence of QSRRs all owed the kinetics of naphthalene and phenanthrene hydrocracking to be represented very satisfactorily, over a wide temperature range, in ter ms of just 17 QSRR parameters. These 17 parameters summarized the chem ical information in 576 rate, equilibrium, and adsorption constants. T hus, the QSRR approach reduced the number of modeling parameters by ab out 97%.