A proton magnetic relaxation study on kinetic isotope effects and hydrogen lifetimes in acid groups of acetic acid and poly (methacrylic acid) in aqueous solutions enriched with 17O

Rates of hydrogen ion exchange between water and L3O+ species, and between water and carboxylic groups of acetic acid or poly(methacrylic acid) in aqueous solutions at several pL-values are reported; where L is used to denote hydrogen and deuterium atoms. It is found that only the second exchange process shows a substantial kinetic isotope effect. This exchange process is interpreted in terms of hydrogen transfer within a hydrogen-bonded complex consisting of one acid group and two watermolecules. (Auth.)