Regular trends in distribution of substituted benzoic acids between organic solvents and water

The influence of physicochemical properties of organic solvents on the distribution constants of aromatic carboxylic acids between the organic and aqueous phases was examined.     

Application of multiparameter equations to calculation of the mutual solubility in water-organic solvent binary systems

The solubility of organic liquids in water and of water in organic liquids is primarily determined by the capability of organic liquids for hydrogen bonding. Adequate generalization of the solubility data is possible only with multiparameter equations taking also into account other properties of organic components, including the cohesion and molar volume.     

Correlation Analysis of the Enthalpies of Vaporization of Isomers with the Hammett-Taft Equation

The enthalpies of vaporization of a series of isomeric compounds containing heteroatoms (ketones, alcohols, halo derivatives) are satisfactorily correlated with the Hammett-Taft equation.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 5, 2005, pp. 783–788.Original Russian Text Copyright © 2005 by Makitra, Polyuzhin.     

Reactions of unsaturated aldehydes with cyclopentadiene in solvents of various polarities

The rate constants of cycloaddition of cyclopentadiene to unsaturated aldehydes in different solvents cannot be correlated with a single parameter, in particular, the Brownstein parameter. The data set can be fitted only by multiparameter equations in which the decisive factor increasing the reaction rate is the capability of a solvent for electrophilic solvation. The same parameter also governs the ratio of the endo and exo isomers of the addition product.     

Effect of Solvation on the Decomposition Rate of Azodiisobutyronitrile

The log rate constants of monomolecular decomposition of azodiisobutyronitrile can be quantitatively correlated with solvent properties by means of linear multiparameter equations including various solvation effects; the key factors are the ability of solvents for electrophilic solvation, which favors decomposition, and cohesive energy density, which unfavors the reaction.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 2, 2005, pp. 196–200.Original Russian Text Copyright © 2005 by Makitra, Polyuzhin, Golovata.     

Solvent effect on the rate of the Mannich reaction of butyraldehyde with formaldehyde

The Mannich reaction of formaldehyde with butyraldehyde and diethylamine in hydrophilic solvents ensuring homogeneity of the medium follows the kinetic relations typical of an irreversible second-order reaction. The rate constants are determined by the ability of solvents to undergo self-association and their electrophilic solvation power; additional inclusion of the solvent polarity via multiparameter Koppel’-Pal’m equation is necessary to obtain a satisfactory quantitative correlation.     

The rate of chloroacetic acid alkaline hydrolysis: Medium effect

Rate constant of chloroacetic acid alkaline hydrolysis in the mixed aqueous-organic solvents depends on the organic co-solvent nucleophilic solvation; however, the effect of the medium polarity on the rate constant is not clear. The rate constant can be reasonably estimated with a multi-parameter equation accounting for the organic co-solvent basicity as well as its density of cohesion energy and molar volume.     

Solvent effects on the decomposition kinetics of peracid esters

Electrophilic solvation that operates to weaken the oxygen-oxygen bond is shown to a factor relating to the effect of the media on the decomposition rate of peracid esters. However, an adequate correlation between reaction rate and solvent properties can only be obtained by means of multiparameter linear equations including various characteristics simultaneously.     

Reaction kinetics of terephthalylchloride with ethylene glycol

The change in the second-order rate constants in the reaction of terephthalyl chloride with ethylene glycol obeys the Michaelis-Menten equation, suggesting that in the first stage a donor-acceptor complex is formed.     

Optimal methods of isolation of biogenic ramnolipid surfactants

Distribution of natural ramnolipid surfactants between 11 solvents and water was studied. It was found that the dependence between the physicochemical characteristics of extractants and the amount of extracted ramnolipids might be described by polyparametric linear equations. Effect of the basicity of extractant is decisive.