'''Aquation''' is the chemical reaction incorporating "one or more integral molecules of water" with or without displacement of other atoms or groups.<ref>{{GoldBookRef |title=aquation |file=A00426 }}</ref> The term is typically employed to refer to reactions of metal complexes where an anion is displaced by water. For example, bromopentaamminecobalt(III) undergoes the following aquation reaction to give a metal aquo complex:<ref>{{Greenwood&Earnshaw2nd}}</ref>
:[Co(NH<sub>3</sub>)<sub>5</sub>Br]<sup>2+</sup> + H<sub>2</sub>O → [Co(NH<sub>3</sub>)<sub>5</sub>(H<sub>2</sub>O)]<sup>3+</sup> + Br<sup>−</sup>
This reaction is catalyzed both by acid and by base. Acid catalysis involves protonation of the bromide, converting it to a better leaving group. Base hydrolysis proceeds by the S<sub>N</sub>1cB mechanism, which begins with deprotonation of an ammonia ligand.
==See also== *Hydration reaction
==References== <references />
Category:Substitution reactions Category:Coordination chemistry Category:Reaction mechanisms Category:Water chemistry