116664-92-7Relevant articles and documents
The Role of Single-Electron Transfer in SN2-Type Substitution Reactions of Anions with Alkyl Halides
Bordwell, F.G.,Harrelson, John A.
, p. 4893 - 4898 (2007/10/02)
Rate constants (kobsd) for reactions of electrophiles with: (a) various carbanions, including 9-substituted fluorenide ions (9-GFl-), 9-substituted xanthenide ions, α-cyano carbanions, anb β-diketo enolate ions, (b) phenothiazinide (PTZ-) and carbazole (Cb-) nitranions, (c) 4-substituted phenoxide ions, and (d) thiphenoxide ions, have been campared with rate constants for single-electron transfer (kSET) calculated using a Marcus-type equation.For both 9-GFl- carbanion and 2-GPTZ- nitranion families reacting with SET acceptors, such as 1,1-dinitrocyclohexane, the kobsd/kSET ratio is near unity.For 9-GFl- carbanions reacting with Ph2CHCl the kobsd/kSET ratios range from 2 to 105, those for 2-PTZ- nitranions from 370 to 1.3*104, and those for Cb- nitranions from 108 to 1010.For reactions of 4-GC6H4O- oxanions with Ph2CHCl the ratios range from 103 for G = Me2N to 1013 for G = CN; for PhS- ion reacting with n-BuBr the ratio is 1017.The significance of these results with respect to the role of an outer sphere SET mechanism in substitution reactions of anions with alkyl halides is discussed.
