deprotonoida

Deprotonoida is the chemical process of removing a proton (H+) from a molecule, typically in the context of acid–base chemistry. In practice, it yields a conjugate base and a conjugate acid of the base: HA + B− → A− + HB. More generally, deprotonation is described in Brønsted–Lowry acid–base theory as a proton transfer from an acid (AH) to a base, leaving behind A− and HB.

The extent of deprotonation depends on the relative strengths of the acid, the base, and the solvent. It is governed by pKa values: a proton is preferentially removed when the conjugate acid of the base is weaker (has a higher pKa) than the original acid. In aqueous solution, common bases like hydroxide readily deprotonate many acids with pKa values below roughly 14, while weaker acids require stronger bases or nonaqueous media.

Common examples illustrate the concept:

- Acetic acid (pKa ≈ 4.8) can be deprotonated by sodium hydroxide to form acetate and water.

- Phenol, with a higher pKa than alkanes, is deprotonated by strong bases such as NaOH to give phenoxide.

- Alcohols are deprotonated only by stronger bases (e.g., NaH) to form alkoxide ions.

- In carbonyl chemistry, deprotonation at the alpha-carbon generates enolates, key intermediates in many reactions.

In biochemistry, deprotonation states influence molecular charge and function; for example, amino acids shift protonation states with pH, affecting solubility and activity. Deprotonoida (the Estonian term) thus describes a fundamental operation in chemistry affecting reactivity, equilibria, and catalysis.