The protonation takes place in the middle of the cyclohexadienyl system.

In particular, he formally considered the ensemble of protonation states.

This positive charge comes from protonation of its free amino groups.

The site of protonation can be very important, for example, for biological activity.

In many systems, both protonation and condensation reactions can occur.

Charge neutralization is an important factor in these protonation reactions.

The resulting benzyne forms addition products, usually by initial protonation.

The origin of the initial protonation step has not been conclusively established.

The state of protonation is usually not specified.

Of these, protonation reactions are the most common.

Protonation of this species then yields the reduced product.

Other investigators have thought the protonation is meta (1,3) to the substituent.

This step is followed by a protonation step to counteract the negative charge.

As the pH increases to approximately 8, the protonation of the imidazole ring is lost.

Subsequent reductive elimination and protonation leads to the product.

The protonation of a monobasic acid will be used to simplify the exposition.

The remaining item for discussion is the final protonation of the cyclohexadienyl anion.

A second reduction immediately follows, after which either protonation or elimination-tautomerization affords the product.

There have been multiple hypotheses about what form the transition state takes before protonation of the C6 carbon occurs to yield the final product.

These words are analogous to protonation and deprotonation, but they have not been widely adopted by chemists.

In 1961 it was found that simple Hückel computations were unable to distinguish between the different protonation sites.

Subsequently, in 1992 and 1996 Birch published twice still suggesting that meta protonation was preferred.

There are known precedents for central anion protonation.

These salts are formed from the protonation or substitution at nitrogen of imidazole.

A lower percentage will correspond with a lower pH because both numbers result from the amount of protonation.