Catalysis of deuterium transfer between liquid chloroform and water by anion-exchange resins

Anion-exchange resins in the hydroxide form have been successfully utilized for catalysis of deuterium transfer between water and liquid chloroform under stirred three-phase slurry conditions. In-solution rate constants for CDCl 3 H 2O exchange obtained at 15–35 °C with liquid chloroform and 0.10 mol/liter NaOH solution under stirred conditions are in good agreement with literature data measured in the absence of bulk chloroform. At 25 °C the resins tested, Rexyn 201(OH) and Ionac ASB-1P(OH), are ~25× more effective per mole of −OH present than NaOH when they are used as whole beads. A further improvement is observed if the beads are crushed, but the latter state would be less suitable for commercial-scale application. The solubility of chloroform in the aqueous phase under isotope-exchange conditions was required to calculate the in-solution rate constants for exchange. A method was developed to obtain chloroform solubilities in 0.10 mol/liter NaOH solution and aqueous resin slurries; equilibrated solution samples were treated with 1 mol/liter NaOH to hydrolyze the dissolved CHCl 3 to chloride ion, which was then analyzed by specific ion electrode.