18522-05-9Relevant academic research and scientific papers
Single Electron Transfer as Rate-Determining Step in an Aliphatic Nucleophilic Substitution
Lund, Torben,Lund, Henning
, p. 470 - 485 (2007/10/02)
The rate of transfer of an electron between electrochemically generated anion radicals and alkyl halides has been measured by cyclic voltammetry and the dependence of the rate on the redox potential of the electron donors found.From this dependence, the rate of electron transfer from an electron donor with reorganization energy about 10 kcal mol-1 to a given alkyl halide can be calculated if the reversible oxidation potential of the donor is known.The method has been applied to show that the rate of the aliphatic nucleophilic substitution of the enolate ion of 4-methoxycarbonyl-4-methyl-1,4-dihydropyridine on t-butyl bromide, neopentyl bromide and adamantyl bromide is the same as that expected for a SET reaction for a donor with the same oxidation potential as the enolate ion.Primary alkyl halides react somewhat faster than expected for a pure SET reaction.The dianion of dihydroperylene reacts with t-butyl chloride and s-butyl bromide at the same rate as would be expected for a SET reaction with a donor with the same oxidation potential as the dianion.The model for the aliphatic nucleophilic substitution is discussed.
