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Deuterium isotope exchange between molecular hydrogen and cyclohexylamine (CHA) has been studied by using the LiCHA, NaCHA, KCHA, and CsCHA salts as catalysts in a stirred reactor over the temperature range -15 to +15 °C.The reaction in solution is very fast (comparable to the amide/ammonia and methylamide/methylamine systems), and even at -15 °C (CHA fp -17.8 °C) rate constants independent of mass transfer could be obtained only for the Li and Na salts in the present apparatus. For these, the kinetic isotope effect (k.i.e., 1.7-2.0) and activation parameter (£a, 11-17 kJ-moM) data have been compared with literature values for base-catalyzed exchange with other protic solvents. Reasons for the observed relative catalyst reactivity LiCHA « NaCHA < KCHA < CsCHA are considered. It has been found that, under some experimental conditions, mass transfer effects can lead to an incorrect k.i.e. value when this is derived from data for a single kinetic run D2 -» HD -H2. The solubility of H2 in CHA has been measured over the temperature range -15 to +15 °C.

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Die Löslichkeit von CHF3 in Wasser und NaOH zwischen 20 und 85°C und 0‐1 .9 molNaOH/1 wird gemessen und zur Bestimmung der Geschwindigkeit des H‐D‐Austauschs zwischen CHF3 und D2O in Lösung verwendet.