288-88-0Relevant articles and documents
Kinetics of hydrolysis in aqueous solution of 1-benzoyl-1,2,4-triazole; the role of pairwise and triplet Gibbs energy interaction parameters in describing the effects of added salts and added alcohols
Noordman, Wouter H.,Blokzijl, Wilfried,Engberts, Jan B. F. N.,Blandamer, Michael J.
, p. 1411 - 1414 (1995)
Kinetic data are reported for the spontaneous hydrolysis of 1-benzoyl-1,2,4-triazole in aqueous solutions at ambient pressure and 298.2 K, in aqueous solutions containing added ethanol, propanol and sodium chloride.Kinetic data are also reported for the same reaction in aqueous mixtures of sodium chloride and ethanol.When either ethanol or propanol are added the rate constant k decreases, plotes of ln(k) vs. molality of alcohol being linear.The patterns are accounted for using pairwise Gibbs energy interaction parameters.The rate constant k decrease more dramatically when sodium chloride is added.This pattern is accounted for using pairwise and triplet interaction parameters.The dependence of rate constant on molality of added ethanol in solutions containing fixed molalities of sodium chloride deviaties from that predicted using the pairwise interaction parameters indicating a non-additivity of salt and alcohol effects on the rate constant.The deviations increase wirh increase in molalities of both added salt and added solvent in a direction consistent with a disruption of the substrate-alcohol hydrophobic interactions by added salt.
SURFACTANT-POLYMER INTERACTIONS AND THEIR EFFECTS ON THE MICELLAR INHIBITION OF THE NEUTRAL HYDROLYSIS OF 1-BENZOYL-1,2,4-TRIAZOLE.
Fadnavis,Engberts
, p. 2636 - 2640 (1984)
Binding of sodium dodecyl sulfate (SDS) to atactic poly(N-vinylpyrrolidone) (PVP) has been studied by conductivity measurements. It is proposed that in addition to normal micelles of SDS an additional pseudophase of mixed micelles of PVP and SDS is present in solution. The effect of polymer-surfactant binding on the catalytic/inhibitive activity of SDS micelles has been investigated by studying the rates of the pH-independent hydrolysis of 1-benzoyl-1,2,4-triazole (1). Though the polymer itself has no effect on the hydrolysis reaction in water, addition of PVP to SDS solutions decreases the micellar inhibition, and pseudo-first-order rate constants (k//o//b//s//d) are higher than those in the absence of PVP. Ultrafiltration experiments using a model substrate indicate increased solubility of the substrate in the micellar pseudophase upon addition of PVP.
Kinetic Medium Effects of Amphiphilic Cosolutes below Their Critical Micelle Concentration: The Effect of Sodium n-Alkyl Sulfates on the Neutral Hydrolysis of 1-Benzoyl-1,2,4-triazole
Noordman, Wouter H.,Blokzijl, Wilfried,Engberts, Jan B. F. N.,Blandamer, Michael J.
, p. 7111 - 7114 (1993)
Kinetic medium effects are presented for sodium n-alkyl sulfates (R = methyl to n-octyl) on the neutral hydrolysis of 1-benzoyl-1,2,4-triazole at 298.15 K in highly aqueous solutions below the critical micellar concentration.The observed rate-decreasing effects are quantitatively analyzed in terms of pairwise solute-solute interactions.It is shown that the effect of the alkyl chains cannot be accounted for on the basis of additivity of pairwise group interactions involving individual methylene moieties.Apparently, the sulfate group shields methylene moieties in close proximity for intermolecular interactions.Methylene groups, further away from the ionic functionality, are shielded less effectively.At the critical micellar concentration of the longer-chain sodium n-alkyl sulfates, the observed medium effects change dramatically as expected on the basis of the onset of micellization.No clear indication for premicellar aggregation was found.The medium effect of the sulfate moiety is estimated by extrapolation of kinetic medium effects to zero methylene groups and appears to be rate-retarding as well.
Effect of Poly(methacrylic acid) Hypercoils on the Neutral and Acid-Catalyzed Hydrolyses of 1-Acyl-1,2,4-triazoles in Aqueous Solution
Jager, Jan,Engberts, Jan B. F. N.
, p. 1474 - 1478 (1985)
Rates and thermodynamic activation parameters have been measured for the neutral and acid-catalyzed hydrolyses of the 1-acyl-1,2,4-triazoles 1-3 in the presence of atactic poly(methacrylic acid) (at-PMAA).Under the employed reaction conditions at-PMAA resides in a coiled, compact conformation.The rates of hydrolysis of the relatively hydrophilic 1-acetyl- (1) and 1-benzoyl-1,2,4-triazole (2) are only little affected by the presence of the polymer.By contrast, the hydrolysis of the hydrophobic 1-benzoyl-3-phenyl-1,2,4-triazole (3) is effectively inhibited as a result of binding of 3 to hydrophobic microdomains within the at-PMAA hypercoil.Only small rate retardations are found for the hydrolysis of 3 in the presence of poly(acrylic acid).The effect of at-PMAA concentration on the rates of hydrolysis of 3 can be described in terms of a kinetic scheme that is essentially a variant of Michaelis-Menten enzyme kinetic formalism.In the presence of at-PMAA, ΔH(excit.) and ΔS(excit.) for the neutral hydrolysis of 3 undergo large and partly compensatory changes, the retardations being dominated by the increase of ΔH(excit.).These findings are interpreted by assuming reduced hydration of the dipolar transition state for hydrolysis in the relatively "dry" hydrophobic microdomains.Comparable results were obtained for the HCl-catalyzed hydrolysis of 3.The inhibitory effect of at-PMAA on this reaction is attenuated in the presence of urea, presumably because of destabilization of the compact conformation of the polymer.
Kinetics of hydrolysis of 1-benzoyl-1,2,4-triazole in aqueous solution as a function of temperature near the temperature of maximum density, and the isochoric controversy
Blandamer, Michael J.,Buurma, Niklaas J.,Engberts, Jan B.F.N.,Reis, Joao C.R.
, p. 720 - 723 (2003)
At temperatures above and below the temperature of maximum density, TMD, for water at ambient pressure, pairs of temperatures exist at which the molar volumes of water are equal. First-order rate constants for the pH-independent hydrolysis of 1-benzoyl-1,2,4-triazole in aqueous solution at pairs of such isochoric temperatures show no unique features. Taken together with previously published kinetic data for the hydrolysis of a range of simple organic solutes in both water and D2O near their respective TMDs, we conclude that special significance in the context of rates of chemical reactions in aqueous solutions should not be attached to the isochoric condition.
ATTEMPTED GENERATION AND STRUCTURE OF THE 4-(1,2,4-TRIAZOYL) CATION
Abramovitch, Rudolph A.,Gibson, Harry H.,Nguyen, Terry,Olivella, Santiago,Sole, Albert
, p. 2321 - 2324 (1994)
4-(and 1-) Amino-1,2,4-triazoles have been treated with nitrosonium tetrafluoroborate or with isoamyl nitrile and acetic acid in the presence of mesitylene.The main product is 1,2,4-triazole, together with a small amount of the 1- and trace amounts of the 4-mesityl derivatives.Ab initio calculations of the putative 4-(1,2,4-triazoyl) cation show the electronic ground state to be a closed shell singlet 1A1 (4? e) (3), with a low-lying 3B1 triplet (4) only 1 kcal/mol above it; the ?-cation (1) is not a local minimum on the potential energy surface.Possible explanations of the results are proposed.
Water-Catalyzed Amide Hydrolysis in Dilute Aqueous Carbohydrate Solutions
Nusselder, Jan Jaap H.,Engberts, Jan B. F. N.
, p. 3159 - 3162 (1987)
Rates and thermodynamics activation parameters were determined for the water-catalyzed hydrolysis of the activated amide bond in three 1-acyl-1,2,4-triazoles of different hydrophobicity by using dilute aqueous solutions of simple carbohydrates as the reaction medium.The solutions show thermodynamically almost ideal behavior.It appears that the kinetic medium effects, and, in particular, the changes in ΔS. are largely determined by carbohydrate-induced alterations in the three-dimensional hydrogen-bond network of water.The specific, hydration model for carbohydrates, developed by Franks and his associates, appears to provide a key to the understanding of the carbohydrate medium effects on the hydrolytic model reaction
Kinetics of Neutral Hydrolysis of Two 1-Acyl-1,2,4-triazoles in Binary Aqueous Mixtures: A Critique of the Evans and Polanyi Proposals Concerning Isochoric Activation Parameters
Haak, Jan R.,Engberts, Jan B. F. N.,Blandamer, Michael J.
, p. 6031 - 6035 (1985)
Kinetic data are reported for hydrolysis of two 1-acyl-1,2,4-triazoles in water and two isodielectric mixtures which belong to different classes of aqueous mixtures.Trends in isothermal and isobaric activation parameters are examined in light of both solute-solvent interactions.Comments by Evans and Polanyi concerning an isochoric constraint are considered.Attention is drawn to the difficulties of satisfying the original criteria and to the possibility of using the internal pressure of the solvent as a way of satisfying in part the requirements of the Evans-Polanyi formalism.
Water-Catalyzed Hydrolysis of 1-Acyl-1,2,4-triazoles in the Presence of Surfactant-Polymer Mixed Micelles. Substrate Dependence of the Effect of Polymer on the Micellar Inhibition
Fadnavis, Nitin W.,Berg, Henk-Jan van den,Engberts, Jan B. F. N.
, p. 48 - 52 (1985)
The water-catalyzed hydrolysis of 1-benzoyl-1,2,4-triazole (1) is inhibited by SDS micelles.Addition of poly(vinylalcohol)-poly(vinyl acetate) copolymers (17percent and 26percent acetate, respectively) leads to a decreased inhibition.As supported by conductivity measurements, the rate effects are attributed to the formation of SDS-copolymer mixed micelles.Ultrafiltration experiments indicate increased binding of the substrate to the mixed micelles.Therefore the copolymer-induced rate accelerations can be best reconciled with an increase in the micropolarity at the substrate binding sites in the mixed micelles relative to unperturbed SDS micelles.With the aid of a computer, all kinetic data can be fitted into a kinetic scheme assuming hydrolysis of 1 in bulk water and in SDS and SDS-copolymer micellar pseudophases.Hydrolysis in SDS-poly(N-vinylpyrrolidone) (PVP) mixed micelles at low SDS concentrations (3-10 mM) was studied with the more hydrophobic substrate 3-phenyl-1-benzoyl-1,2,4-triazole (3).Now the SDS-induced inhibition is further increased by the polymer.Kinetic analysis shows that 3 is less strongly bound to mixed SDS-PVP micelles than to SDS micelles but that the rate constants in both micellar pseudophases are rather similar.It is argued that the different behavior of 1 and 3 in the mixed micelles primarily reflects the large propensity of 3 for stabilization by hydrophobic interactions.
Remarkably Distinctive Recognition of α-Alanine and α-Phenylalanine during the Water-Catalyzed Hydrolysis of an Activated Amide
Streefland, Lisette,Blandamer, Michael J.,Engberts, Jan B. F. N.
, p. 5769 - 5771 (1995)
The rate of the water-catalyzed hydrolysis of three activated amides in aqueous solution is significantly retarded by small amounts of α-phenylalanine as compared with the rate acceleration induced by other common α-amino acids not containing a benzyl group in their side chain.These contrasting effects emphasize the large hydrophobicity of α-phenylalanine and are of relevance for a better quantitative understanding of protein folding and molecular recognition processes involving proteins.
