CHBE 551 Lecture 20. Unimolecular Reactions. Last Time Transition State Theory. Transition state theory generally gives preexponentials of the correct order of magnitude. Transition state theory is able to relate barriers to the saddle point energy in the potential energy surface;
where GVT is the number of vibrational states at the transition state, with an energy between E‡ and E*. NV(E*) is the number of vibrational states of the reactants with an energy between E* and E* +E ; qR‡ is the rotational partition function for the transition state and qR* is the rotational partition function for the excited products.
A comparison of the experimental rate of isomerization of stilbene (C6H5)C=C(C6H5) to the predictions of the RRKM model