Kinetic studies of the hydrolysis of furfurylidene benzoylhydrazone

Abu-Eid, Maher; Mahmoud, Foad M.S.; Al-Nuri, Mohammed; Zuhri, Ali Z. Abu

doi:10.1007/bf00811745

Cited by 4 publications

(6 citation statements)

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“…The variation in absorbance with time for the hydrolysis of salicylidenebenzoyl hydrazone in different solvents is shown in Figure (1). It can be seen from Figure (1) that a good linear correlation was obtained when a plot of ln(A t -A cd versus time was performed( A t is the obsorbance at time t and A oo is the absorbance at time infinity-This indicates that the hydrolysis of salicylidenebenzoyl hydrazone in 5% (V/V) solvent to buffer mixture is considered as first order kinetics. In all runs, the rate constant was obtained from the slope of the linear plot.…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

“…The effect of solvent nature on the rate constant of hydrolysis was studied and the results obtained are listed in Table (1). It can be seen fromn Table (1) that the rate constant, k, increases gradually by increasing the dielectric constant, 0, of the protic solvents, whereas dimethyl sulphoxide does not follow this variation. On the other hand, Figure (2) shows a linear plot between log k and 1/0 for the hydroxylic solvents with a deviation of the point corresponding to the formation of complexes between dimethyl sulphoxide and water.…”

Section: Resultsmentioning

confidence: 99%

“…In a previous work [1], the effect of molecular stucture and pH on the hydrolysis of substituted benzylidenebenzoyl hydrazones(SBH) was studied. As a continuation of this work, it was decided to investigate the effect of different solvents on the kinetics and mechanism of the hydrolysis of SBH.…”

Section: Introductionmentioning

confidence: 99%

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The Role of Solvent on the Kinetics and Mechanism of the Hydrolysis of Salicylidene Benzoyl Hydrazone

Abu-Eid¹

1988

An-Najah University Journal for Research - A

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The effect of various solvents on the kinetics and mechanism of the hydrolysis of Salicylidene Benzoyl hydrazone (SBH) has been studied at five different temperatures (17-45 C) using U.V. and visible spectrophotometry. In both protic and aprotic solvents, the hydrolysis rates follow first order kinetics. The role of solvent on the reaction rate, thermodynamic parameters and mechanism have been reported and discussed.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The Role of Solvent on the Kinetics and Mechanism of the Hydrolysis of Salicylidene Benzoyl Hydrazone

Abu-Eid¹

1988

An-Najah University Journal for Research - A

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“…Such be hav iour can be ob served un der con di tions in which the substrate ex ists as a free base and can un dergo at tack by pro tons, so that a gen eral acid-base ca tal y sis mech a nism is pos tu lated in Scheme I for the hy dro ly sis of com pounds un der in ves ti gation in uni ver sal buffer acidic me dia which is sim i lar to the mech a nism pro posed by many work ers for sim i lar sys tems. [24][25][26] Such mech a nism in volves the con ver sion of the hydrazone com pound to its con ju gate acid (-CH=NH-NH-) in a rapid pre-equilibrium step fol lowed by the slow at tack of H 2 O mole cule (Scheme I).…”

Section: Re Sults and Discussionmentioning

confidence: 99%

Spectrophotometric and Polarographic Studies on the Kinetics of Hydrolysis of N‐(6‐Methyl‐5‐Nitropyridin‐2‐yl Methylidene)‐N′‐(Substituted Thiazol‐2‐yl)Hydrazines

El-Nady

2001

J Chinese Chemical Soc

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The kinetics of the hydrolysis of hydrazone de rived from nitropyridine 2‐carboxaldehyde and 2‐hydrazino‐4‐substituted thiazoles Ia‐e in 10% (v/v) DMF‐buffer mixture has been investigated by applying two in dependent and different techniques viz UV‐spectrophotometry and differential pulse, polarography (DPP). The hydrolysis has been found to follow general acid‐base catalysis. Mechanism for the hydrolysis in acidic medium has been postulated. The observed rate constants, activation and thermodynamic parameters for the hydrolysis have been calculated. The effects of pH, molecular structure, temperature and change in percent age of water in the DMF‐buffer mixture on the rate of hydrolysis have been discussed.

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Controlled Release of Volatile Aldehydes and Ketones from Dynamic Mixtures Generated by Reversible Hydrazone Formation

Levrand¹,

Fieber²,

Lehn³

et al. 2007

Helvetica Chimica Acta

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Delivery systems generated by reversible hydrazone formation from hydrazine derivatives (see Fig. 1) and carbonyl compounds in H 2 O efficiently increase the long-lastingness of volatile aldehydes and ketones (R 1 R 2 C¼O) in various perfumery applications. The hydrazones are usually obtained in an (E) configuration at the imine double bond (NHN¼C) and, in the case of aliphatic acylhydrazones R'COÀNHÀN¼CR 1 R 2 (R' ¼ alkyl), as syn and anti conformers with respect to the amide bond (COÀNHN). An average free-energy barrier of ca. 78 kJ/mol was determined for the amide-bond rotation by variable-temperature 1 H-NMR measurements ( Fig. 2). In the presence of H 2 O, the hydrazone formation is entirely reversible, reaching an equilibrium composed of the hydrazine derivative, the carbonyl compound, and the corresponding hydrazone. Kinetic measurements carried out by UV/VIS spectroscopy showed that the same equilibrium was reached for the formation and hydrolysis of the hydrazone. Rate constants are strongly pH-dependent and increase with decreasing pH ( Table 1). The influence of the hydrazine structure on the rate constants is less pronounced than the pH effect, and the presence of surfactants reduces the rate of equilibration (Tables 1 and 3). The full reversibility of the hydrazone formation allows to prepare dynamic mixtures by simple addition of a hydrazine derivative to several carbonyl compounds. Dynamic headspace analysis on dry cotton showed that the presence of a hydrazine derivative significantly increased the headspace concentrations of the different carbonyl compounds as compared to the reference sample without hydrazine ( Table 4). The release of the volatiles was found to be efficient for fragrances with high vapor pressures and low H 2 O solubility. Furthermore, a special long-lasting effect was obtained for the release of ketones. The simplicity of generating dynamic mixtures combined with the high efficiency for the release of volatiles makes these systems particularly interesting for practical applications and will certainly influence the development of delivery systems in other areas such as the pharmaceutical or agrochemical industry.

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Kinetic studies of the hydrolysis of furfurylidene benzoylhydrazone

Cited by 4 publications

References 10 publications

The Role of Solvent on the Kinetics and Mechanism of the Hydrolysis of Salicylidene Benzoyl Hydrazone

The Role of Solvent on the Kinetics and Mechanism of the Hydrolysis of Salicylidene Benzoyl Hydrazone

Spectrophotometric and Polarographic Studies on the Kinetics of Hydrolysis of N‐(6‐Methyl‐5‐Nitropyridin‐2‐yl Methylidene)‐N′‐(Substituted Thiazol‐2‐yl)Hydrazines

Controlled Release of Volatile Aldehydes and Ketones from Dynamic Mixtures Generated by Reversible Hydrazone Formation

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