Transition-state theory gives $k=(k_BT/hc^\circ)\exp(\Delta S^{\ddagger}/R)\exp(-\Delta H^{\ddagger}/RT)$. Using the bimolecular gas-phase standard-state relation $E_a=\Delta H^{\ddagger}+2RT$, the Arrhenius prefactor is $A=e^2(k_BT/hc^\circ)\exp(\Delta S^{\ddagger}/R)$. Therefore ΔS‡=R ln[Ahc°/(e²kBT)]≈−12.66 J/(mol K). The e² factor is required for the gas-phase bimolecular convention used by the key.
More Kinetics and Reaction Dynamics: Elementary, parallel, opposing, and consecutive reactions. Steady state approximation. Mechanism of complex reactions. Unimolecular reactions. Potential energy surface and classical trajectories, Concept of saddle points, Transition state theory: Eyring equation, thermodynamic aspects. Kinetics of polymerization. Catalysis concepts and enzyme catalysis. Kinetic isotope effects. Fast reaction kinetics: relaxation and flow methods. Diffusion controlled reactions. Kinetics of unimolecular and bimolecular photophysical processes, Quantum yield calculation, static and dynamic quenching. questions
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