DEUTERIUM ISOTOPE EFFECTS IN THE BROMINE OXIDATION OF ETHANOL AND OF ACETALDEHYDE
The rate of oxidation of ethanol-1,1-d/sub 2/ by bromine in aqueous solution has been measured over a range of alcohol concentrations from one to 41% by weight, and over a pH range from two to ten. In unbuffered acid solution the ratio of the rates of oxidation of ordinary to that of dideutero alcohol is close to four, proving that a methylene C--H bond is broken in the rate-determining step of the reaction. From the isotope effect and the reaction kinetics it is concluded that ethyl hypobromite plays no role in the oxidation of ethanol, neither as the precursor of acetaldehyde nor as the active oxidant. Under the same conditions acetaldehyde is oxidized at a rate four times that of acetaldehyde-1-d, in accord with the suggestion that the aldehyde is oxidized, via its hydrate, by a mechanism very similar to that for ethanol. At pH 5.5 and 10.3 the isotope effects for the alcohol oxidation are 2.4 and 3.0, respectively. The significance of these lower values cannot be assessed in the absence of detailed knowledge of the reaction products and kinetics under these conditions. (auth)
- Research Organization:
- Argonne National Lab., Lemont, Ill.
- Sponsoring Organization:
- USDOE
- NSA Number:
- NSA-12-012273
- OSTI ID:
- 4329294
- Journal Information:
- Journal of the American Chemical Society (U.S.), Journal Name: Journal of the American Chemical Society (U.S.) Vol. Vol: 80; ISSN JACSA
- Country of Publication:
- Country unknown/Code not available
- Language:
- English
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