Lobna Abdel-Mohsen Ebaid Nassr

Sohag University · Department of Chemistry

The kinetics of the acid hydrolysis reaction of Fe(II)-bis(salicylidene) complexes were followed under pseudo-first-order conditions ([H+] >> [complex]) at 298 K. The ligands of the studied azomethine complexes were derived from the condensation of salicylaldehyde with different five -amino acids. The hydrolysis reactions were studied in acidic med...

The importance of 6-aminocoumarin, d-glucose, and ethyl cyanoacetate in pharmaceutical field was documented in literatures. Therefore, 6-aminocoumarin was reacted with single and double molarity of d-glucose forming Schiff’s base and bis-compound derivatives. Also, it was reacted with CS2 in phase transfer catalysis condition producing dithiocarbam...

Five novel Cu(II) complexes derived from the condensation between 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine, l-phenylalanine, L-aspartic acid, L-histidine and L-arginine) were synthesized and characterized by their elemental analyses, thermogravimetric analysis, IR, mass and electronic spectra, conductance and magnetic measurements....

Kinetic study of acid hydrolysis of some hydrophilic Fe(II) Schiff base amino acid complexes with antibacterial properties was performed using spectrophotometry. The Schiff base ligands were derived from sodium 2-hydroxybenzaldehyde-5-sulfonate and glycine, L-alanine, L-leucine, L-isoleucine, DL-methionine, DL-serine, or L-phenylalanine. The reacti...

Kinetics of acid-catalyzed hydrolysis of some high-spin Fe(II) Schiff base amino acid complexes were followed spectrophotometrically at 298 K under pseudo–first-order conditions. The studied ligands were derived from the condensation of 5-bromosalicylaldehyde with different four amino acids (phenylalanine, aspartic acid, histidine, and arginine). T...

The effect of salts on the reactivity of base hydrolysis of Fe(II) chelates bis(naphthylidene alanate) (nali), bis(naphthylidene phenylalanate) (nphali), bis(naphthylidene aspartate) (nasi), (naphthylidene histidinate) (nhi), bis(naphthylidene arginate) (nari) has been investigated in aqueous media containing alkali metal halides viz. LiBr, NaCl, K...

The effect of salts on reactivity of basic hydrolysis of Fe(II) chelates bis(naphthylidenealanate) (nali), bis(naphthylidenephenylalanate) (nphali), bis(naphthylideneaspartate) (nasi), (naphthylidene histidinate) (nhi), bis(naphthylidene arginate) (nari) has been studied in aqueous media containing alkali metal halides, LiBr, NaCl, KBr, tetramethyl...

Five novel Cu(II) complexes derived from the condensation between 5-bromosalicylaldehyde (bs) and α-amino acids (L-alanine, l-phenylalanine, L-aspartic acid, L-histidine and L-arginine) were synthesized and characterized by their elemental analyses, thermogravimetric analysis, IR, mass and electronic spectra, conductance and magnetic measurements....

Salt effects on the kinetics of acid hydrolysis of some novel hydrophilic iron(II) complexes have been investigated in aqueous medium. The ligands are derived from the condensation of amino acids (glycine, L-alanine, L-leucine, L-isoleucine, DL-methionine, DL-serine or L-phenylalanine) and sodium 2-hydroxybenzaldehyde-5-sulfonate. The reaction was...

The kinetics of the oxidation of some Fe(II)–Tris Schiff base complexes by peroxydisulfate was studied spectrophotometrically in the aqueous medium and in the organic–aqua binary mixture. The inspected complexes were derived from the condensation of 2-acetylpyridine and substituted benzylamines. The oxidation reaction of the studied complexes was f...

The reactivity of few novel high-spin Fe(II) complexes of Schiff base ligands derived from 2-hydroxynaphthaldehyde and some variety of amino acids with the OH− ion has been examined in an aqueous mixture at the temperature range from 10 to 40°C. Based on the kinetic investigations, the rate law and a plausible mechanism were proposed and discussed....

Kinetic study of some novel high spin Fe(II) complexes of Schiff base ligands derived from 5-bromsalicyaldehyde and amino acids with the OH− ion and DNA has been carried out. Based on the kinetic data, the rate law and a plausible mechanism were proposed. Kinetic data of the base catalyzed hydrolysis imply pseudo first-order double stage process du...

The kinetics of base-catalyzed hydrolysis of 7-dimethylamino-4-methyl-2H-chromen-2-one (DMAC) and 7-diethylamino-4-methyl-2H-chromen-2-one (DEAC) in binary water-methanol and water-acetone mixtures were studied in the temperature range from 288 to 313 K. The activation and thermodynamic parameters of these reactions were evaluated and discussed. Th...

The kinetics of hydroxide ion attack on bis(bromosalicylidene alanate)iron (II) (bsali), bis(bromosalicylidene phenylalanate)iron(II) (bsphali), bis(bromosalicylidene aspartate)iron(II) (bsasi), (bromosalicylidene histidinate)iron(II) (bshi), bis(bromosalicylidene arginate)iron(II) (bsari) have been reported in different binary aqueous solvent mixt...

In the present study, reactivity base-catalyzed hydrolysis of 7-dimethylamino-4-methyl-2H-chromen-2-one (DMAC) and 7-diethylamino-4-methyl-2H-chromen-2-one (DEAC) in binary aqueous-methanol and aqueous-acetone mixtures was examined at 298 K. Kinetic results, rate laws and reaction mechanisms were established. Moreover, the change in the activation...

Base-catalyzed hydrolysis of coumalic acid (COU) in binary aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at a temperature range from 283 to 313 K. Moreover, the change in the activation energy barrier of COU from water to water–methanol and water–acetone mixtures is estimated from the kinetic data. Solvent effects on re...

New series of Fe(II) complexes and Schiff base amino acids have been designed and synthesized from the bioactive ligands by condensation of 5-bromo-2-hydroxybenzaldehyde and α-amino acids (l-alanine (ala), l-phenylalanine (phala), l-aspartic acid (aspa), l-histidine (his) and l-arginine (arg)). Elemental analyses, infrared, ultraviolet–visible spec...

We have investigated the kinetics of hydroxide ion attack at iron(II) chelates with 5-bromosalicylidene derivatives of amino acids (alanine, phenylalanine, aspartic acid, histidine, and arginine) in binary aqueous mixed solvents at 298 K. The observed reactivity trends are discussed in connection with the complexes hydrophobicity/hydrophilicity, tr...

Kinetics of acid hydrolysis of seven antibacterial iron(II) Schiff base complexes has been studied. The Schiff base ligands were derived from sodium 2-hydroxybenzaldehyde-5-sulfonate and a series of amino acids. The hydrolysis rate is studied by spectrophotometric method and compared with complex hydrophilicity. Addition of the organic co-solvent,...

The reactivity of few novel high spin Fe(II) complexes of Schiff base ligands derived from 2-hydroxynaphthaldehyde and some variety of amino acids with OH- ion has been examined in aqueous mixture at temperature in the range 10–40 Co. Based on the kinetic investigations, the rate law and a plausible mechanism were proposed and discussed. The genera...

Rate constants for the base hydrolysis of bis(naphthylidene alanate)iron (II) (nali), bis(naphthylidene phenylalanate)iron(II) (nphali), bis(naphthylidene aspartate)iron(II) (nasi), (naphthylidene histidinate)iron(II) (nhi), bis(naphthylidene arginate)iron(II) (nari) have been reported in different binary aqueous solvent mixtures at 298 K. The obse...

A series of new Iron(II) Schiff base amino acid complexes derived from the condensation of amino acid and sodium 2-hydroxybenzaldehyde-5-sulfonate have been synthesized. The complexes were characterized by elemental, electronic, IR spectral analyses and conductance measurements. The stability and solubility of the prepared complexes were determined...

Kinetics of the base hydrolysis of 6-nitro-2H-chromen-2-one (NC) and 6-nitro-2H-chromen-2-one-3-carboxylic acid (NCC) in water-methanol and water-acetone mixtures was studied at temperature range from 283 to 313 K. The activation parameters of the reactions were evaluated and discussed. The change in the activation barrier of the investigated compo...

Base hydrolysis of 7-hydroxy-2H-chromen-2-one (HC) and 7-hydroxy-2H- chromen-2-one-4-acetic acid (HCA) in aqueous-methanol and aqueous-acetone mixtures were studied kinetically at temperature range from 283 to 313 K. The activation parameters of the reactions were evaluated and discussed. Moreover, the change in the activation energy barrier of the...

Base-catalyzed hydrolysis of 6-nitro-2H-chromen-2-one (NC) and 6-nitro-2H-chromen-2-one-3-carboxylic acid (NCC) in binary water/methanol and water/acetone mixtures were studied kinetically at 298 K. The changes in the activation barrier of the investigated compounds from water to water/methanol and water/acetone mixtures were estimated from the kin...

During the oxidation of polygalacturonate methyl ester polysaccharide by MnO4− in highly basic medium, the formation of the green polygalacturonate methyl ester (PGME-Mn(VI)O42−) and the blue (PGME-Mn(V)O43−) intermediates were followed spectrophotometrically. In this paper, the kinetics of the decay of the green (PGME-Mn(VI)O42−) intermediate, the...

Kinetics of aquation of some Fe(II) Schiff base amino acid complexes was followed spectrophotometrically. The Schiff base ligands were derived from salicylaldehyde and isoleucine, leucine, serine, methionine, tryptophan, or histidine. The reaction was studied in aqueous media, aqua–propanol mixtures, and in the presence of different concentrations...

The kinetics of formation of the green manganate(VI) intermediate complex formed during the oxidation of pectin polysaccharide (poly galacturonate methyl ester) (PGME) by MnO4- in alkaline solution at pH⩾12 have been studied. The rate law was suggested to be: rate=kobs.[MnO4-]. The reaction was found to be base – catalyzed and fractional second – o...

AbstractNew ternary complexes of Mn(II) with py, bipy, and terpy as primary ligand (L1) and 2′,4′,5′,7′-tetraiodofluorescein (I4FlCOOH) as secondary ligand (L2) were prepared. The stoichiometry for these complexes was found to be Mn(II):L1:L2=1:2:1, and the complex formula proposed is [Mn(L1)2(I4FlCOO)]+. The effect of substituent groups of L2 and...

The kinetics and mechanism of the reaction of hydrogen peroxide with some Fe(II) Schiff base complexes were investigated spectrophotometrically in aqueous solution at pH 8 and 35 degrees C under pseudo-first-order conditions. The used ligands were derived from salicylaldehyde or o-hydroxynaphthaldehyde and some amino acids (l-leucine, l-iso-leucine...

Rate constants for base hydrolysis of both coumarin and thiocoumarin have been studied in different binary aqueous-methanol mixtures at temperature range from 288 to 313 K. The activation parameters of the reactions were evaluated. Moreover, the change in the activation barrier of the investigated compounds from water to water-methanol mixtures wer...

A series of some new cobalt(II) and nickel(II) ternary complexes of N-(acetyl)phenylalaninate (acphe), N-(acetyl)tyrosinate (actyr), N-(benzoyl)leucinate (bzleu), N-(benzoyl)phenylalaninate (bzphe), N-(tosyl)glutamic acid (tsglu), N-(tosyl)arginine (tsarg) with certain N-heterocyclic ligands such as imidazole (imi), methylimidazole (mimi), 2,2′-bip...

Rate constants for base hydrolysis of bis(naphthylidene isoleucinate)iron (II) (nili), bis(naphthylidene leucinate)iron(II) (nli), bis(naphthylidene serinate)iron(II) (nsi), bis(salicylidene isoleucinate)iron(II) (sili), (salicylidene leucinate)iron(II) (sli), bis(salic- ylidene methioninate)iron(II) (smi), and (salicylidene tryptophanate)iron(II)...

Salt effects on the reactivity of base hydrolysis of Fe(II) chelates [naphthylideneisoleucinate (nili), naphthylideneleucinate (nli), naphthylideneserinate (nsi), salicylideneisoleucinate (sili), salicylideneleucinate (sli), salicylidenemethioninate (smi), and salicylidenetryptophanate (sti)] have been investigated in aqueous media containing alkal...

New Fe(II) complexes of N-salicylidene- and N-naphthylidene-amino acids (H2L) were prepared and characterized by elemental, electronic and IR spectral analyses, conductance and magnetic moment measure- ments and spectrophotometric determination of the stoichiometry. The stability and solubility of the prepared complexes were determined. The investi...

The reactivity against OH− ion of some novel Fe(II) complexes of Schiff base ligands derived from salicylaldehyde or o-hydroxynaphth-aldehyde and some variety of amino acids has been examined in aqueous and aqua-ethanol mixtures. The rate law and relevant mechanism were assumed. Base hydrolysis kinetics measurements revealed pseudo-first-order doub...