Specific influence of salts on the hydrolysis reaction rate of p-nitrophenyl anthranilate in binary acetonitrile–water solvents

Bayissa, Leta Danno; Ohmae, Yoshihito; Hojo, Masashi

doi:10.1016/j.molliq.2014.09.004

Cited by 13 publications

(8 citation statements)

References 43 publications

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“…A slight rate enhancement is observed for NaNO 3 and Na 2 SO 4 , whereas NaCl and KCl show an apparent retarding effect. The decrease in the rate constant with the addition of chloride ions is reported due to the drying effect where the addition of added salts reduces the concentration of water molecules, which interact in the transition state . The influence of the nucleophilic effect of Cl − ions on the reaction rate can be examined by using another buffer system at pH 2, which lacks Cl − ions.…”

Section: Resultsmentioning

confidence: 99%

Kinetics and Mechanism of the Thermal and Hydrolytic Decomposition Reaction of Rosocyanin

John

Rugmini

Nair

2018

Int J of Chemical Kinetics

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Spiroborate esters of curcumin find applications in the field of medicinal and analytical chemistry. The present paper reports the hydrolytic and thermal stability of rosocyanin, a 1:2 spiroborate ester of curcumin used for the photometric estimation of boron in different matrices. The effect of temperature, pH, and solvents was monitored spectrophotometrically for the hydrolysis of rosocyanin. The reaction followed first‐order kinetics, and the reaction rate enhanced with an increase in the percentage of water in an aqueous organic mixture, temperature, and pH. 11B NMR and UV–visible spectra were used to identify the hydrolysis product. The possible mechanistic route for the hydrolysis of rosocyanin was proposed. Solid‐state stability of rosocyanin was investigated by thermogravimetric analysis, and the data were analyzed using different solid‐state reaction models to find the suitable reaction model. Kinetic parameters associated with its thermal decomposition were calculated using Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose isoconversional methods and were compared.

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Section: Resultsmentioning

confidence: 99%

Kinetics and Mechanism of the Thermal and Hydrolytic Decomposition Reaction of Rosocyanin

John

Rugmini

Nair

2018

Int J of Chemical Kinetics

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“…The following overall nucleophilicity order for the S N 2 mechanism (in protic solvents) has been reported: I − > CN − > OH − > N 3 − > Br − > ArO − > Cl − > pyridine > AcO − > H 2 O . In the previous paper , we have reported that tetraalkylammonium chloride and bromide accelerate the hydrolysis reaction of p ‐nitrophenyl anthranilate (2‐aminobenzoate) in aqueous and binary MeCN‐H 2 O mixed solutions. In addition, it has been established that anion exchange reactions between Cl − and Br − from a substrate or added salts cause remarkable rate changes (acceleration and deceleration) in solvolyis reactions of organic halides in binary solvents between water and organic solvents .…”

Section: Resultsmentioning

confidence: 99%

“…The added salt can potentially lead to either rate acceleration or retardation depending upon the substrate, types of the salt, and their concentrations as well as the reaction mechanisms. We have reported the significant changes in the hydrolysis (solvolysis) reaction rates of various organic compounds (S N 1, S N 2, and S N 1–S N 2 intermediate substrates) in binary solvent media containing added salts. Several factors potentially contribute to the changes in the hydrolysis rates.…”

Section: Introductionmentioning

confidence: 99%

“…Several factors potentially contribute to the changes in the hydrolysis rates. These includes the changes in “normal” water structure , the increase in the hydroxide ion (OH − ) activity , and coordination interaction between alkali metal or alkaline earth metal ions and the anion left from a substrate in the “modified” reaction media .…”

Section: Introductionmentioning

confidence: 99%

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Influences of Micelle Formation and Added Salts on the Hydrolysis Reaction Rate of p‐Nitrophenyl Benzoate in Aqueous Buffered Media

Bayissa

Ohmae

Hojo

2016

Int J of Chemical Kinetics

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The hydrolysis reaction rate of p-nitrophenyl benzoate (p-NPB) has been examined in aqueous buffer media of pH 9.18, containing surfactants, cetyltrimethylammonium bromide (CTAB) and chloride (CTAC), or sodium dodecyl sulfate (SDS) at 35°C. Although the rate constant [log (k/s −1 )] of p-NPB hydrolysis has once decreased slightly below the critical micelle concentration (CMC) value for CTAB and CTAC, it has begun to increase drastically with micellar formation. With increasing concentrations larger than the CMC value, the log (k/s −1 ) value has reached the optimal value, i.e., a 140-and 200-fold rate acceleration for CTAB and CTAC, respectively, compared to that without a surfactant. Whereas the anionic surfactant, SDS, has caused only a gradual rate deceleration in the whole concentration range (up to 0.03 mol dm −3 ). Increases in pH of the buffer have resulted in increases of the hydrolysis rate. In the CTAB micellar solution, the remarkably enhanced rate has been retarded significantly by the addition of only 0.10 mol dm −3 bromide salts. The effects of rate retardation caused by the added salts follows in the order of NaBr > Me 4 NBr > Et 4 NBr > Pr 4 NBr > n-Bu 4 NBr. In the absence of surfactant, however, the addition of the bromide salts has accelerated the hydrolysis rate, except for the metallic salt of NaBr, with the order of Me 4 NBr < Et 4 NBr < Pr 4 NBr < n-Bu 4 NBr. In the CTAC micellar solution, similar rate retardation effects have been observed in the presence of chloride salts (NaCl, Et 4 NCl, and n-Bu 4 NCl). The effects of added salts have

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“…[2,3,5] There are different factors can affect hydrolysis, include pH, salt concentration, temperatures and solvolysis time which have been reported in detail. [4,[6][7][8][9][10][11][12] Several methods, including conductometric, pH titration, [5,13,14] spectrophotometry, [15][16][17] and ion-exclusion based chromatographic [9,18] have been used to determine the hydrolytic rate of several compounds. [12,17,[19][20][21] As far as we know, the solvolysis rate of hydrazine and its derivatives have not been studied, especially for hydrazine hydrochloride salts.…”

Section: Introductionmentioning

confidence: 99%

Solvolysis Thermodynamic Parameters of Phenyl Hydrazine Hydrochloride

Abdolla

El–Dossoki

2021

Alfarama Journal of Basic & Applied Sciences

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The present work deals with studying the effect of solvent and temperature on the solvolysis process using both the pH-metric and the conductometric measurements. The pH and the conductivity of different concentrations of the phenyl hydrazine hydrochloride in water (H 2 O), ethanol (EtOH) and in (EtOH-H 2 O) mixtures with different percentages of EtOH; 30%, 50%, 70%, 100% (v/v) and at different temperatures from 293.15 to 308.15 K with a step of 5 K were measured experimentally. The conductivity of different concentrations of the phenyl hydrazine hydrochloride in aniline at the same temperatures was also measured. Depending on the measured pH and conductivity data, the solvolysis constant of phenyl hydrazine chloride was estimated. The thermodynamic parameters (free energy change, , enthalpy change, , entropy change, , and activation energy, ) of the solvolysis process were evaluated from the temperature dependence of solvolysis constant. Positive values of the standard enthalpy change (), indicate that the solvolysis process is endothermic process. The solvolysis constant is increase as the alcohol percentage increase from 30% -100%, which attributed to the higher solute-solvent interaction.

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Specific influence of salts on the hydrolysis reaction rate of p-nitrophenyl anthranilate in binary acetonitrile–water solvents

Cited by 13 publications

References 43 publications

Kinetics and Mechanism of the Thermal and Hydrolytic Decomposition Reaction of Rosocyanin

Kinetics and Mechanism of the Thermal and Hydrolytic Decomposition Reaction of Rosocyanin

Influences of Micelle Formation and Added Salts on the Hydrolysis Reaction Rate of p‐Nitrophenyl Benzoate in Aqueous Buffered Media

Solvolysis Thermodynamic Parameters of Phenyl Hydrazine Hydrochloride

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