Alkaline hydrolysis of methyl hydrogen malonate in water-organic solvents

1986 ◽  
Vol 51 (6) ◽  
pp. 1187-1194 ◽  
Author(s):  
Oľga Grančičová ◽  
Vladislav Holba ◽  
Ľudmila Beluská

Kinetics of alkaline hydrolysis of methyl hydrogen malonate in water-methanol, water-dioxane, water-tert-butyl alcohol and water-ethylene glycol mixtures was examined. The valuse of the transfer functions of the activated complex δmμ≠ from water to the first two mixed media were calculated from the measured solubilities of tetrabutylammonium hydrogen malonate, the activation Gibbs energies and the known values of transfer functions for tetrabutylammonium and hydroxide ions. Some conclusions concerning the effect of a nonaqueous component of the solvent on solvation of the reactants and the activated complex have been drawn from the experimental data obtained.

1993 ◽  
Vol 58 (5) ◽  
pp. 1001-1006 ◽  
Author(s):  
Oľga Vollárová ◽  
Ján Benko

The kinetics of oxidation of [Co(en)2SCH2COO]+ with S2O82- was studied in water-methanol and water-tert-butyl alcohol mixtures. Changes in the reaction activation parameters ∆H≠ and ∆S≠ with varying concentration of the co-solvent depend on the kind of the latter, which points to a significant role of salvation effects. The solvation effect on the reaction is discussed based on a comparison of the transfer functions ∆Ht0, ∆St0 and ∆Gt0 for the initial and transition states with the changes in the activation parameters accompanying changes in the CO-solvent concentration. The transfer enthalpies of the reactant were obtained from calorimetric measurements.


1998 ◽  
Vol 63 (3) ◽  
pp. 293-298
Author(s):  
Vladislav Holba

The solubilities of cesium dianilinetetraisothiocyanatochromate(III) in water as well as in aqueous methanol, isopropyl alcohol, tert-butyl alcohol and acetonitrile were measured as a function of temperature and solvent composition. The Gibbs energies, enthalpies and entropies of transfer of the salt from water to the given solvents have been evaluated from experimental data. The contribution of [Cr(C6H5NH2)2(NCS)4]- ion to the Gibbs energy of transfer of the investigated salt has been calculated using the tetraphenylarsonium tetraphenylborate (TATB) reference electrolyte assumption.


1980 ◽  
Vol 45 (5) ◽  
pp. 1485-1494 ◽  
Author(s):  
Ján Benko ◽  
Vladislav Holba

The alkaline hydrolysis of diphenic acid monomethyl ester was studied in mixtures of water with methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, tert-butyl alcohol, and acetone. The dependences of the rate constant on the concentration of the nonaqueous component at different temperatures were obtained and the activation parameters at an isodielectric composition of the reaction medium were determined. The influence of the ionic strength on the reaction rate in the mentioned media was studied and conclusions were drawn as to the role of specific interactions between the reacting ions in the kinetics and mechanism of the studied reaction.


1980 ◽  
Vol 45 (3) ◽  
pp. 720-726 ◽  
Author(s):  
Stanislav Ševčík ◽  
Miroslav Kubín ◽  
Jiří Štamberg

The paper reports alkaline hydrolysis of ethylene dipivalate and 2-hydroxyethyl pivalates as compounds modelling the structural unit and crosslinking site of hydrophilic gels, i.e. copolymers of 2-hydroxyethyl methacrylate and ethylene dimethacrylate. The kinetics of hydrolysis was investigated in water-acetone solutions containing respectively 50, 75, 80, 85 and 90% by vol. (related to 20°C) of acetone at 20, 30, 40, and 50°C. It was demonstrated that, owing to steric hindrance, the preferential hydrolysis of monoester was more pronounced in the case of pivalic esters of ethylene glycol compared with acetic esters of ethylene glycol. The results are discussed in connection with the selectivity of the alkaline hydrolysis of ester bonds in "pendant" parts of structural units in hydrophylic methacrylate gels.


1988 ◽  
Vol 53 (6) ◽  
pp. 1268-1273
Author(s):  
Ján Benko ◽  
Oľga Vollárová

The kinetics of alkaline hydrolysis of 3,4-thiophenedicarboxylic acid monomethyl ester has been studied in mixed solvents water-methyl alcohol, water-tert-butyl alcohol, and water-dioxane. The specific effects causing different courses of these dependences have been evaluated. The greatest changes in the thermodynamic activation parameters have been observed in the medium of water-methyl alcohol.


2021 ◽  
Author(s):  
Do Young Maeng ◽  
V. Faye McNeill

Manuscript with supporting information describing novel experimental data on the alkaline hydrolysis of synthetic esters, relevant to chemistry in the indoor environment


2021 ◽  
Author(s):  
Do Young Maeng ◽  
V. Faye McNeill

Manuscript with supporting information describing novel experimental data on the alkaline hydrolysis of synthetic esters, relevant to chemistry in the indoor environment


1980 ◽  
Vol 45 (11) ◽  
pp. 2873-2882
Author(s):  
Vladislav Holba ◽  
Ján Benko

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.


1994 ◽  
Vol 59 (8) ◽  
pp. 1738-1744
Author(s):  
Vladislav Holba

The solubilities of tetraalkylammonium dianilinetetraisothiocyanatochromates(III) (alkyl = methyl, ethyl, 1-propyl, and 1-butyl) in water, water - methanol, water - tert-butyl alcohol and water - acetonitrile solutions were measured at 25 °C. The results were used to evaluate the activity coefficients and Gibbs energies of transfer of the saturating salts from water to the mixed systems. The Gibbs energies of transfer of the [Cr(C6H5NH2)2(NCS)4]- ion were obtained by means of known ionic transfer functions for the tetraalkylammonium ions based on the TATB assumption.


2000 ◽  
Vol 65 (9) ◽  
pp. 1455-1463
Author(s):  
Oľga Vollárová ◽  
Ján Benko

The solubility, partial molar volume and standard integral molar enthalpy of solution of cis- and trans-[CoCl2(en)2]Cl in water, aqueous methanol, aqueous tert-butyl alcohol and aqueous acetonitrile are reported. The transfer functions ∆Gt0, ∆Ht0 and T∆St0 as well as partial molar volumes are used to obtain information on the solute-solvent interactions. Results obtained are discussed in terms of differences in the surface charge distribution in isomeric coordination species.


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