lobna.nassr

Lobna Abdel-Mohsen Ebaid Nassr

Professor - Head Of Chemistry Department- Director of Quality Management Unit - Faculty of Science - Sohag University

Faculty of science

Address: Chemistry Department - Faculty of Science - Sohag University

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Hydrophobicity and kinetic inspection of hydroxide ion attack on some chromen-2-one laser dyes in binary aqueous–methanol and aqueous–acetone mixtures: Initial state-transition state analysis
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 energy barrier of the investigated compounds from water to water–methanol and water–acetone mixtures was estimated from the kinetic data. Base-catalyzed ... Read more

2015 | Keywords structure effects, salt effects,
Kinetic study of the base-catalyzed hydrolysis of novel high-spin hydrophobic Fe(II) – azomethine amino acid chelates: Salt and structure effects on the reactivity
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, tetramethylammonium bromide (TMAB), tetraethylammonium bromide (TEAB), and tetrabutylammonium bromide (TBAB). The suggested mechanism of the base hydrolysis involves the parallel attack of OH−ions ... Read more

2015 | Keywords Azomethine,
Salts and structural effects on the base catalyzed hydrolysis of some novel and pharmacologically active Iron(II) azomethine amino acid complexes
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, KBr, Tetramethylammonium bromide (TMAB), Tetraethylammonium bromide (TEAB) and Tetrabutylammonium bromide (TBAB). The suggested mechanism of the base hydrolysis reaction ... Read more

Kinetic and mechanistic aspects of reactivity of the oxidation of some Fe(II)–tris Schiff base complexes by peroxydisulfate: Spectrophotometric tracer and solvent effect on the reactivity
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 followed at 303 K under pseudo–first-order conditions. It was found that ... Read more

Reactivity trends and kinetic inspection of hydroxide ion attack and DNA interaction on some pharmacologically active agents of Fe(II) amino acid Schiff base complexes at different temperatures
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. The general rate equation ... Read more

Kinetic study and reactivity trends of hydroxide ion attack on some chromen-2-one laser dyes in binary water–methanol and water–acetone mixtures
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, transfer chemical potentials of hydroxide ion and the complex, and the solvent effects. Read more

Kinetic study of the hydroxide ion attack on and DNA interaction with high spin iron(II) Schiff base amino acid chelates baering ONO donors
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 due to the ... Read more

2014 | Keywords Iron(II) complexes, Hydrophilic,
Effect of bromide salts on the acid hydrolysis of anti-bacterial hydrophilic Schiff base amino acid Iron(II) complexes
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 studied under conditions of pseudo first order kinetics. The general rate equation was suggested as ... Read more

2014 | Keywords bromosalicylidene, DNA binding,
Metal based pharmacologically active agents: Synthesis, structural characterization, molecular modeling, CT-DNA binding studies and in vitro antimicrobial screening of Iron(II) bromosalicylidene amino acid chelates
In recent years, great interest has been focused on Fe(II) Schiff base amino acid complexes as cytotoxic and antitumor drugs. Thus a series of new iron(II) complexes based on Schiff bases amino acids ligands have been designed and synthesized from condensation of 5-bromosalicylaldehyde (bs) and a-amino acids (L-alanine (ala), L-phenylalanine (phala), L-aspartic acid (aspa), L-histidine (his) and L-arginine (arg)). The ... Read more

Design, characterization, teratogenicity testing, antibacterial, antifungal and DNA interaction of few high spin Fe(II) Schiff base amino acid complexes
In this study,newFe(II) Schiff base amino acid chelates derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized via elemental, thermogravimetric analysis, molar conductance, IR, electronic, mass spectra and magnetic moment measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. Correlation of all spectroscopic data suggested that Schiff ... Read more