Deuterium isotope exchange between carboxylic acids and hydrogen

The catalytic exchange of deuterium between carboxylic acids and hydrogen according to RCOOH(l) + HD(g)⇋RCOOD(l)+H2(g), where R=H or CH3, has been studied with the acids in the pure state at various temperatures, and in solutions of carbon tetrachloride at 25°C. The hydroxyl hydrogen of the acids is about 3–4 times more enriched in deuterium than the hydrogen gas. The measured isotope effects are discussed in terms of molecular force field calculations for formic and acetic acid.