khalaf.ali

Khalaf Ali Fayez Abuamra

استاذ - أستاذ متفرغ

كلية العلوم

العنوان: قسم النبات والميكروبيولوجى -كلية العلوم -جامعة سوهاج

2

إعجاب

المنشورات و المؤلفات التي تحتوي علي الكلمة المفتاحية: Activation energy barrier


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 ... إقراء المزيد

Reactivity Trends and Kinetic Inspection of Hydroxide Ion Attack and DNA Interaction on Some Pharmacologically Active Agents of Fe(II)  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 ... إقراء المزيد

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 ... إقراء المزيد

2018-09-16 15:07:32 الكلمات المفتاحية 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. ... إقراء المزيد

Kinetics, reactivity, initial-transition state analysis and thermodynamic parameters of base-catalyzed hydrolysis of coumalic acid in solvents with different polarities
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 reactivity trends have been analyzed into initial and transition ... إقراء المزيد

2018-08-30 19:39:42 الكلمات المفتاحية 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. ... إقراء المزيد