33560-61-1Relevant academic research and scientific papers
DETERMINATION OF THE NUCLEOPHILICITY PARAMETERS N+ OF THE ETHOXIDE ION IN MIXTURES OF ETHANOL WITH NONPOLAR SOLVENTS
Sinev, V. V.,Strel'nikova, G. I.
, p. 1729 - 1732 (2007/10/02)
On the basis of data on the kinetics of the reaction of triarylmethyl ions with alkali-metal ethoxides in ethanol-dioxane and ethanol-benzene solvent systems it was shown that Ritchie's equation can be used to describe the effect of the nature of the medium on the kinetics of the process.The obtained values of the nucleophilicity parameters N+ for systems containing an ethoxide ion can be used to calculate the rate constants for the ethoxylation of various substrates (bimolecular mechanism) in ethanol and in its mixtures with nonpolar solvents.
EFFECT OF IONIC ASSOCIATION ON THE KINETICS OF THE REACTION OF TRIARYLMETHYL CATIONS WITH ALKALI-METAL ETHOXIDES IN MIXED SOLVETS
Sinev, V. V.,Strel'nikova, G. I.
, p. 987 - 992 (2007/10/02)
The kinetics of the reaction of triarylmethyl ions with sodium and potassium ethoxides in binary ethanol-dioxane and ethanol-benzene systems were studied by a spectrophotometric method.A method is proposed for the separation of the observed rate constants into ion and ion-pair components.It was shown that the effect of the solvent polarity on the ionic components of the kinetic parameters of reactions of the investigated type agrees quantitatively with electrostatic theory.
The Relative Electrophilic Reactivities of Tropylium Cation and its (OC)3M ?-Complexes: Kinetic Studies of Alkoxide Transfer and Reversible Nucleophilic Addition
Lal, Kasturi,Leckey, Nigel T.,Watts, William, E.,Bunton, Clifford A.,Mhala, Marutirao M.,Moffatt, John R.
, p. 1091 - 1098 (2007/10/02)
?-Complexation of the tropylium cation (Tr)(1+) with an (OC)3Cr group increases thermodynamic stability (ΔpKR+ ca. 4.3 in methanol) and reduces reactivity towards abstraction of methoxide ion from Malachite Green methyl ether (MG)OMe (krel. ca. 110) in MeNO2 - MeCOEt (40:60 v/v) and nucleophilic exoaddition of methanol (krel. ca. 2100) in methanol.The organometallic cation (1a) is stable in aqueous solutions of pH(1+), (1+), and (1+) in MeNO2-MeCOEt (40:60 v/v) are 1:10:6, respectively.The rates of transfer to (Tr)(1+) of alkoxide ion from (η-7-exo-alkoxycycloheptatriene)Cr(CO)3 complexes (2a-d) in MeCN decrease through the series: alkoxy=methoxy>ethoxy>isopropoxy>t-butoxy, but the overall rate change is only about five-fold.In methanol, the 7-exo-methoxycycloheptatriene complex (2a) is about ten times more reactive towards acid heterolysis than is methyl tropyl ether.This conversion is general acid-catalysed.In aqueous solutions of pH>ca. 6, the rate of spontaneous heterolysis of the ether (2a) is substantially faster than that of consumption of the resulting cation (1a) which increases with increasing pH.The 7-endo-methoxy stereoisomer (3) is inert to acid heterolysis in aqueous solutions to give cation (1a), but undergoes decomplexation to give (Tr)(1+).
