Hydrogen isotope exchange between fluoroform (CF3H) and water. 2. Catalysis by hydroxide ion in the presence of added dimethyl sulfoxide

Hydrogen isotope exchange between fluoroform (CF3H) and water. 4. Catalysis by NaOH and anionic resin above 100 °C as an alternative to DMSO addition for rate enhancement

“…1; the latter set will be valid if the mass transfer effect can be eliminated by more efficient gas/liquid mixing. For comparison, some data are included for representative aqueous DMSO systems near the solubility-limited, maximum NaOH concentrations (4). Because the exchange reaction is first order in -OH (3), the higher [NaOH] possible in pure water will give shorter reaction half-lives (3).…”

“…I I Efficient catalysis of deuterium transfer to gaseous fluo-CF3D was prepared in batches by NaOD-catalyzed reaction of CF,H 1 roform from a natural deuterium source like liquid water will with D 2 0 as already described (4). Stock NaOH solutions were pre-I be a vital pan of any heavy water production process based on pared by diluting Fisher Scientific concentrates with deionized dis-:…”

“…The effectiveness of a variety of both Services Ltd., Huntsville, Ontario) was converted to the hydroxide form and analyzed for base strength by standard column techniques homogeneous and heterogeneous for exchange with (6). This strong base resin is recommended for continuous use up to water has been studied (3)(4)(5) surements have now been extended U P to 14O0C, to determine form sample analysis and data treatment methods were the same as how high a reaction temperature would be needed to achieve used previously (3).…”

Hydrogen isotope exchange between fluoroform (CF3H) and water. 3. Catalysis by −OH-type anion exchange resins, and the effect of added dimethyl sulfoxide

“…Overall, the effect of the resin on CF,H solubility in the bulk water-DMSO solutions is slight. These small corrections were applied to the available solubility data for the pure solvent mixtures (2), to obtain the in-slurry solubilities (actually for the bulk liquid) required for calculation of in-slurry exchange rate constants (see below).…”

“…The use of dimethyl sulfoxide (DMSO) as cosolvent with water has been shown to enhance the relatively poor catalytic activity of the hydroxide ion ( 1 ) for this reaciisn by a factor of lo6 (2). Such a base-catalyzed deuterium exchange step could be employed in the CFIH redeuteration stage of a heavy water production process based on isotopeselective, infrared-laser-induced, multiphoton dissociation of CFlD/CF3H mixtures (3).…”