PREEXPONENTIAL FACTORS FOR SOLID-STATE THERMAL DECOMPOSITION

The preexponential factors for both unimolecular and bimolecular solid-state thermal decompositions are analyzed from the point of view of activated complex theory. The effect of molecular rotation in both the reactants and the activated complex is considered. If the activated complex has freer rotation than the reactant, the first-order preexponential factor is high. In the bimolecular case, the activated complex is likely to have restricted rotations leading to very low pseudo-first-order preexponential factors. This approach is compared with other treatments.