ahmedabudief

Dr. Ahmed Mohamed Abu-Dief

Professor - Professor of Physical and Inorganic Chemistry

Faculty of science

Address: Behind hospital of Sohag University - Ali Ebn Abi Taleb Street

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Reactivity trends in the base hydrolysis of 6-nitro-2H-chromen-2-one and 6-nitro-2H-chromen-2-one-3-carboxylic acid at different temperatures

2012 | Keywords Order Rate Constant, base hydrolysis, Pyrone Ring, Organic Cosolvent, Reactivity Trend,
Reactivity trends in the base hydrolysis of 6-nitro-2H-chromen-2-one and 6-nitro-2H-chromen-2-one-3-carboxylic acid at different temperatures
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 compounds from water to water-methanol and water-acetone mixtures were estimated from the kinetic data. ... Read more

Solvent Effects on The reactivity Trends of some Coumarin Derivatives

2012 | Keywords Kinetics, Temperature, solvent effect, Coumarin Derivatives, thermodynamic parameters, Activation energy barrier, base hydrolysis, initial state transition state,
Solvent Effects on The reactivity Trends of some Coumarin Derivatives
Kinetic results, rate laws and reaction mechanisms were established for the base hydrolysis of 7-hydroxycoumarin (HC), 7-hydroxycoumarin-4-acetic acid (HCA), 6-nitrocoumarin (NC), 6-nitrocoumarin-3-carboxylic acid (NCC), 7-dimethylamino-4-methylcoumarin (DMAC), 7-diethylamino-4-methylcoumarin (DEAC) and coumalic acid (COU) in aqueous solution, water-methanol and water-acetone mixtures. The kinetics of the base hydrolysis followed a rate law with kobs= k2[OH-] for all coumarin derivatives under study except 6-nitrocoumarin-3-carboxylic ... Read more

Synthesis, Characterization, DNA Binding Studies and Embryos toxicity of Some Novel Iron(II) Amino Acid Schiff base complexes

2012 | Keywords Iron(II), amino acid, Embryos toxicity, DNA binding, IR, TGA, CHN, Molar coductivity, anti,
Synthesis, Characterization, DNA Binding Studies and Embryos toxicity of Some Novel Iron(II) Amino Acid Schiff base complexes
New Fe(II) Schiff base amino acid complexes derived from the condensation of o-hydroxynaphthaldehyde with L-alanine, L-phenylalanine, L-aspartic acid, L-histidine and L-arginine were synthesized and characterized by elemental analysis, IR, electronic spectra, and conductance measurements. The stoichiometry and the stability constants of the complexes were determined spectrophotometrically. The investigated Schiff bases exhibited tridentate coordination mode with the general formulae [Fe(HL)2]·nH2O. But ... Read more

Initial State and Transition State Contributions to Reactivity Trends of Base-Catalyzed Hydrolysis of Some Nitro Chromen-2-One Derivatives

2011 | Keywords Initial state, Transfer chemical potential, Activation energy barrier, Base-catalyzed hydrolysis, Chromene-2-Ones,
Initial State and Transition State Contributions to Reactivity Trends of Base-Catalyzed Hydrolysis of Some Nitro Chromen-2-One Derivatives
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 kinetic data. Solvent effects on the reactivity trends were analyzed into initial state and transition state components. These ... Read more

Kinetics of Base Hydrolysis of Some Chromen-2-one Indicator Dyes in Different Solvents at Different Temperatures

2011 | Keywords Kinetics, Activation energy barrier, solvent effect, base hydrolysis mechanism, Hydroxy-chromen-2-ones,
Kinetics of Base Hydrolysis of Some Chromen-2-one Indicator Dyes in Different Solvents at Different Temperatures
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 investigated compounds from water to water-methanol and water-acetone mixtures was estimated from the kinetic data. ... Read more

Solvent effects on the kinetics and reactivity trends of base-catalyzed hydrolysis of some chromen-2-one indicator dyes at different temperatures

2011 | Keywords base hydrolysis, Kinetic parameters, solvent effect, Chromen-2-ones, Dyes,
Solvent effects on the kinetics and reactivity trends of base-catalyzed hydrolysis of some chromen-2-one indicator dyes at different temperatures
Base hydrolysis of 7-hydroxy coumarin (HC) and 7-hydroxy-coumarin-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 investigated compounds from water to water-methanol and water-acetone mixtures was estimated from the kinetic ... Read more

Kinetics, Reactivity, Initial–Transition State Analysis and Thermodynamic Parameters of Base-Catalyzed Hydrolysis of Coumalic Acid in Solvents of Different Polarities

2011 | Keywords solvent effect, Kinetics, methanol, acetone, base hydrolysis,
Kinetics, Reactivity, Initial–Transition State Analysis and Thermodynamic Parameters of Base-Catalyzed Hydrolysis of Coumalic Acid in Solvents of Different Polarities
Base-catalyzed hydrolysis of coumalic acid (COU) in aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at 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 reactivity trends have been analyzed into initial and transition state components. ... Read more

Transfer chemical potentials, solubility and reactivity of 6-Nitro-2H-chromen-2-one and 6-Nitro-2H-chromen-2one-3-carboxylate anion

2010 | Keywords initial state transition state, 6-Nitro-2H-chromen-2-one, Reactivity, solubility, Transfer chemical potential,
Transfer chemical potentials, solubility and reactivity of 6-Nitro-2H-chromen-2-one and 6-Nitro-2H-chromen-2one-3-carboxylate anion
Kinetic results, rate laws and reaction mechanisms were established for the base hydrolysis of 6-nitrocoumarin (NC), 6-nitrocoumarin-3-carboxylic acid (NCC), in aqueous solution, water-methanol and water-acetone mixtures. The kinetics of the base hydrolysis followed a rate law with kobs= k2[OH-] for all coumarin derivatives under study except 6-nitrocoumarin-3-carboxylic acid (NCC) which followed a rate law with kobs= k1+ k2[OH-]. The kinetic ... Read more

Solvent and Temperature effects on Reactivity trends of Base-catalyzed hydrolysis of some Chromen-2-one laser dyes

2010 | Keywords solvent effect, base hydrolysis, Chromen-2-ones, laser dyes,
Solvent and Temperature effects on Reactivity trends of Base-catalyzed hydrolysis of some Chromen-2-one laser dyes
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 hydrolysis ... Read more