# Questions tagged [transition-state-theory]

Questions related to explanations of the reaction rates of elementary chemical reactions. The theory assumes a special type of chemical equilibrium (quasi-equilibrium) between reactants and activated transition state complexes.

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### Ambimodal transition states in some organic reaction pathways

In many computational studies, mechanisms appear to have so-called ambimodal transition states, i.e. a transition state which can lead to multiple products, in conflict to the common undergraduate ...
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### Transition state and free energy

We have products $\ce{A + B}$ combining to form $\ce{C + D}$ through the transition state $\ce{X}$. Are all reactions at least virtually reversible? Is the difference between a reversible reaction ...
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### Why are the total energies of transition states so commonly corrected for zero-point vibrational energy?

So often I see total energies of transition states corrected for zero-point vibrational energy which always confuses me. Zero point energy is the lowest energy that a ground state minimum energy ...
223 views

### Finding chair and boat transition states during ring-forming reactions

Reactions that form 6 membered rings most commonly go via either boat or chair transition states but the products themselves do not necessarily adopt the same conformation as the TS. I'm attempting ...
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### Units of rate constant (cycles per second vs radians per second) in Eyring equation

In the Eyring equation (EE), $$k = \frac{k_\mathrm B T}{h} \exp\left(\frac{-\Delta G_{\mathrm f}}{RT}\right),$$ the units of $k$ are $\mathrm{s^{-1}}$. However, in general rate constants are usually ...
254 views

### Transition state optimisation on the surface of periclase

I want to model a reaction catalysed by periclase ($\ce{MgO}$) using DFT. I have a good guess on the transition state (TS) of the reaction that goes in gas phase/solvent (produced using MOPAC). The ...
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### If Gibbs energy of activation is positive, how is the change to the transition state possible?

The Gibbs energy increases from the reactants to the transition state, but according to the Second Law of Thermodynamics, entropy of the universe can only increase. Why is the transition state ...
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### Explaining boiling using internal energy

Internal energy is summation of potential and kinetic energies of a substance Using this interpretation of internal energy, how can I explain boiling? Kinetic remains constant. Potential should ...
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### Explain the difference between reaction intermediate and reactive intermediate

Wikipedia definitions of the terms: Reaction intermediate: https://en.m.wikipedia.org/wiki/Reaction_intermediate Reactive intermediate: https://en.m.wikipedia.org/wiki/Reactive_intermediate What ...