48129-94-8Relevant articles and documents
RATES OF DEPROTONATION OF (4-NITROPHENYL)ACETONITRILE AND (2-4-DINITROPHENYL)ACETONITRILE IN 50% Me2SO--50% WATER.
Bernasconi,Hibdon
, p. 4343 - 4348 (1983)
Rates of reversible deprotonation of (2,4-dinitrophenyl)acetonitrile (2-(NO//2)//2) by OH** minus , water, piperidine, morpholine, cacodylate, acetate, formate, and chloroacetate ion and of (4-nitrophenyl)acetonitrile (2-NO//2) by OH** minus , piperidine, morpholine, n-butylamine, and 2-methoxyethylamine in 50% Me//2SO-50% water at 20 degree C are reported. The intrinsic rate constant (in the Marcus sense) for the dinitro derivative is about 10-fold lower than that for the mononitro compound. This is consistent with the stronger charge delocalization in the anion of the dinitro compound, which leads to greater structural/electronic/solvational reorganization during the reaction. Bronsted beta //B values (variation of base) for the deprotonation by piperidine and morpholine are 0. 50 for 2-(NO//2)//2 and 0. 74 for 2-NO//2, respectively. Bronsted alpha //C//H values (variation of C-H acid) are 0. 47 for deprotonation by morpholine and 0. 35 for deprotonation by piperidine.
Proton transfer from carbon acids to carbanions. 1. Reactions of various carbon acids with the anions of substituted benzylmalononitriles in 90% Me2SO-10% water. determination of intrinsic barriers of identity reactions from the marcus relationship
Bernasconi, Claude F.,Ni, Jiu Xiang
, p. 5060 - 5066 (2007/10/02)
A kinetic study of the reversible deprotonation of 9-cyanofluorene (2), 1,3-indandione (3), 4-nitrophenyl-acetonitrile (4), (3-nitrophenyl)nitromethane (5), and (4-nitrophenyl)nitromethane (6) by the anions of substituted benzylmalononitrile (1-X-) in 90% Me2SO-10% water (v/v) at 20 °C is reported. Intrinsic rate constants and intrinsic barriers of these reactions have been determined by extrapolation or interpolation of Br?nsted plots whose slopes (β) are all close to 0.5. Intrinsic barriers of the identity reactions CH + C- ? C- + CH (CH = 2,3,4,and phenylnitromethane) have been estimated on the basis of the Marcus equation, coupled with either a plausible value for the identity barrier of the reaction AH+ + A ? A + AH+ (A = piperidine or morpholine) ("amine method") or a plausible value for the identity barrier of the reaction 2 + 2- ? 2- + 2 ("9-cyanofluorene method"). There are discrepancies in the identity barriers for CH + C- ? C- + CH (CH = 2, 3, 4, and phenylnitromethane) calculated by the two methods. Possible reasons for these discrepancies and the significance of the results in terms of the validity and scope of the Marcus equation are discussed.
Intrinsic Reactivities of Some Carbanions in ?-Adduct Forming Reactions
Crampton, Michael R.,Stevens, Andrew J.
, p. 1715 - 1720 (2007/10/02)
Kinetic and equilibrium data are reported for nucleophilic attack in methanol at unsubstituted ringpositions of 1,3,5-trinitrobenzene, 2,4,6-trinitrotoluene and 1-chloro-2,4,6-trinitrobenzene by carbanions derived from dimethyl malonate, ethyl cyanoacetate and 4-nitro-, 4-cyano- and 2-cyanobenzyl cyanides.The results are used to determine intrinsic reactivities for the carbanions in these ?-adduct forming reactions and are discussed in terms of the electronic and solvent reorganisation occurring during reaction.
