Select "reaction coordinates" to show the potential energy curve between the substituted and (less stable) unsubstituted cyclohexanes [2].

The curve of the substituted cyclohexane is nearly symmetrical. There is a small maximum associated with the boat conformation and two small minima associated with the so-called twist-boat conformation.

Statistical thermodynamics determines the population ratios of the different conformations in the course of chemical reactions, as molecules change into the more stable conformations. The elimination reaction is not reversible because the cyclohexene (isopropylcyclohexene), highlighted in red, is the only chemical compound remaining after the other products vaporize.

By selecting "elimination reaction" you can observe reaction kinetics characteristic of E2 elimination reactions of 6-carbon cyclic compounds. The elimination reaction in this case proceeds exclusively in anti mode and therefore a hydrogen is detached from the molecule according to Hofmann's rule [3], even if the most stable cyclohexene (by Zaitsev's rule [4]) does not form.

As the reaction takes place, the hydrogen (gray sphere) and chlorine (green sphere) are detached and dispersed in the reaction vessel. They go off screen as we are not interested in them anymore; while chlorine remains in the solution, the hydrogen tends to form a new bond with a strong base (bond in blue color).

Use the "reaction progress" slider to observe how the C-Cl and C-H bonds break simultaneously to form two new bonds: the double bond and the H-B bond between the hydrogen and the nucleophile that behaves as a strong base.