Hydrogen Transfers Involving Pre-equilibria

According to Eigen s scheme of H-transfer [52] in solution the reaction partners have first to meet in order to react. For an intermolecular H-transfer from AH to B one can write 

35) electrical charges are omitted, k represents the intrinsic forward rate constant. The pre-equilibrium constant is given by 

Equation (6.37) predicts changes in the apparent reaction order as a function of Cft and Cg. It can easily be shown that 

For the case of two proton donors AH of the same kind which exchange two protons in a cyclic dimer (AH)2 the following equation has been derived 

Finally, the intramolecular case is interesting, where AH and B are functional groups of the same molecule. The equilibrium constant between the non-reactive form AH -1- B and the reactive form AHB is given by 

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