oxidation | An-Najah Staff

The Catalytic Activity of Poly(Siloxane)-Supported Metalloporphyrins in Olefin Oxidation ‎Reactions: The Effect of The Support on the Catalytic Activity and Selectivity

Mon, 2014-03-24 14:44 — Shukri Mohammed Khalaf

Journal Title, Volume, Page:

Journal of Molecular Catalysis A: Chemical, Volume 113, Number 1, pp. 35-44(10)

Year of Publication:

1996

Link:

http://www.ingentaconnect.com/content/els/13811169/1996/00000113/00000001/art000...

Authors:

Khalaf, S.

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Jondi, W.

Hilal, H.S.

Keilani, A.

Suleiman, M.

Schreiner, A.F.

Preferred Abstract (Original):

Supported tetra(-4-pyridyl)porphyrinato-manganese(III)[Mn^III(TPyP)]⁺ and -tin(IV)[Sn^IV(TPyP)]²⁺ have been prepared. The solid support was iodonated poly(siloxane) surface prepared by condensation reactions of (EtO)₄Si with (MeO)₃Si(CH₂)₃I. The supported metalloporphyrins were employed as catalysts for the oxidation reactions of l-octene and of cyclohexene. NaBH₄ was used to reduce [Mn^III(TPyP)]⁺ and [Sn^IV(TPyP)]²⁺ back to their catalytically active Mn^II and Sn^II forms, respectively. Contrary to their homogeneous counterparts, both of the supported metalloporphyrins catalysed the cyclohexene oxidation reaction to yield only 2-cyclohexen-1-one with no other products over a reaction time of 10 h. In addition to cyclohexene oxidation, the supported [Mn^III(TPyP)]⁺ catalysed l-octene oxidation as well, whereas the supported [Sn^IV(TPyP)]²⁺ was inactive for the oxidation of l-octene.

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Kinetics and Mechanism of Oxidation of L-Cysteine by Ferrozineiron(III) Complex in Aqueous Acidic Medium

Sun, 2014-03-23 11:13 — Bassem Shraydeh

Journal Title, Volume, Page:

J. Saudi Chem. Soc., Vol. 10, No. 2; pp. 271-284

Year of Publication:

2006

Authors:

Bassem Sharydeh

Chemistry Department, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Ismail Warad

Chemistry Department, An-Najah National University, Nablus, Palestine

Maher Abu Eid

Chemistry Department, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

Kinetic oxidation of L-cysteine by [Fe(Fz)2] 1- complex was carried out in acidic medium under pseudo rate conditions. The molar ratios between iron(III), iron(II) and Ferrozine (HFz) complexes in absence and presence of L-cysteine were individually determined using job's method. The formation of [Fe2+-Fz] at lmax = 562nm was spectrophotometrically followed during this kinetic study. The reaction is found to be first-order with respect to iron(III) and L-cysteine, second-order with respect to HFz-1 ligand and reversed second-order with respect to hydrogen ion concentrations. The salts effect was determined and no radical species have been detected. The kobs rose when the temperature was increased which empowered the activation parameters of the rate-determining step calculations. A reaction mechanism and rate law derivation are proposed with a pre-equilibrium of an adduct formation between L-cysteine and [Fe3+-Fz] complex.

Osmium(VIII)-Catalyzed Oxidation of Some Cyclic Amines by Potassium Hexacyanoferrate(III) in Alkaline Media: a Kinetics and Mechanistic Study

Mon, 2014-02-03 10:36 — Mohammad Musmar

Journal Title, Volume, Page:

Chemistry of Heterocyclic Compounds April 2003, Volume 39, Issue 4, pp 478-484

Year of Publication:

2003

Link:

http://link.springer.com/article/10.1023%2FA%3A1024765330259

Authors:

M. M. Al-Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

W. J. Jondi

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

A. A. Amer

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. Hannoun

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

M. J. Musmar

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Reactions of morpholine, piperidine, and piperazine with Os(VIII)-catalyzed hexacyanoferrate(III) in alkaline media to produce the corresponding lactam have been studied at constant temperature and ionic strength. The reactions followed first-order kinetics with respect to [amine] and [Os(VIII)] but were independent of [Fe(CN)₆ ^3-] and [OH^-]. The effects of introduced electrolytes, potassium hexacyanoferrate(II), relative permitivity, and temperature have also been studied. A mechanism accounting for these results has been proposed.

Oxidation of some Alicyclic Amines by Potassium Hexacyanoferrate (III) in Alkaline Medium: A Kinetic and Mechanistic Study

Mon, 2014-02-03 10:16 — Mohammad Musmar

Journal Title, Volume, Page:

Journal of Molecular Catalysis A Chemical. 10/2013; 39(1):1-11

Year of Publication:

2013

Authors:

M. M. Al-Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

A. A. Amer

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

W. J. Jondi

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. Hanoun

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

M. J. Musmar

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Oxidation of some alicyclic amines (morpholine, piperazine and piperidine) by potassium hexacyanoferrate( ) in basic medium has been investigated at 35 ° C. Stoichiometric results showed that four moles of hexacyanoferrate(III) were consumed per mole of piperidine or morpholine whereas piperazine consumed eight moles of the oxidant to produce the corresponding lactams. Kinetic studies indicated that piperidine and morpholine also followed different kinetics from that of piperazine, being first order in the amine concentration and independent of the concentrations of hexacyanoferrate( ) and hydroxide ion, while in the case of piperazine, the reaction was first order in both oxidant and substrate concentrations and zero order with respect to the concentration of hydroxide ion. The changes in reaction rate due to changing ionic strength of the medium as well as other factors has also been investigated. The activation parameters of the oxidation process have been evaluated and a mechanism consistent with the observed kinetics has been proposed.

Oxidation of Some Alicyclic Amines by Potassium Hexacyanoferrate (III) In Alkaline Medium: A Kinetic and Mechanistic Study

Thu, 2014-01-30 14:59 — Mohammad Musmar

Journal Title, Volume, Page:

An-Najah University Journal for Research - Natural Sciences - Volume 15, Issue 1, 2001

Year of Publication:

2001

Link:

http://scholar.najah.edu/publication/journal-article/oxidation-some-alicyclic-am...

Authors:

M. M. Al-Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

A. A. Amer

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

W. J. Jondi

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. Hanoun

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

M. J. Mus

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Oxidation of some alicyclic amines (morpholine, piperazine and piperidine) by potassium hexacyanoferrate(III) in basic medium has been investigated at 35°C. Stoichiometric results showed that four moles of hexacyanoferrate(III) were consumed per mole of piperidine or morpholine whereas piperazine consumed eight moles of the oxidant to produce the corresponding lactams. Kinetic studies indicated that piperidine and morpholine also followed different kinetics from that of piperazine, being first order in the amine concentration and independent of the concentrations of hexacyanoferrate(III) and hydroxide ion, while in the case of piperazine, the reaction was first order in both oxidant and substrate concentrations and zero order with respect to the concentration of hydroxide ion. The changes in reaction rate due to changing ionic strength of the medium as well as other factors has also been investigated. The activation parameters of the oxidation process have been evaluated and a mechanism consistent with the observed kinetics has been proposed.

Oxidation of some Alicyclic Amines by Potassium Hexacyanoferrate (III) in Alkaline Medium: A Kinetic and Mechanistic Study

Mon, 2014-01-06 10:01 — Mohammed Al-Subu'

Journal Title, Volume, Page:

An-Najah University Journal for Research - Natural Sciences - Volume 15, Issue 1, 2001

Year of Publication:

2001

Link:

http://scholar.najah.edu/publication/journal-article/oxidation-some-alicyclic-am...

Authors:

M.M. Al-Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

A. A. Amer

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

W. J. Jondi

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. Hanoun

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M.J. Musmar

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

Oxidation of some alicyclic amines (morpholine, piperazine and piperidine) by potassium hexacyanoferrate(???) in basic medium has been investigated at 35°C. Stoichiometric results showed that four moles of hexacyanoferrate(III) were consumed per mole of piperidine or morpholine whereas piperazine consumed eight moles of the oxidant to produce the corresponding lactams. Kinetic studies indicated that piperidine and morpholine also followed different kinetics from that of piperazine, being first order in the amine concentration and independent of the concentrations of hexacyanoferrate(???) and hydroxide ion, while in the case of piperazine, the reaction was first order in both oxidant and substrate concentrations and zero order with respect to the concentration of hydroxide ion. The changes in reaction rate due to changing ionic strength of the medium as well as other factors has also been investigated. The activation parameters of the oxidation process have been evaluated and a mechanism consistent with the observed kinetics has been proposed. Keywords: Hexacyanoferrate(???), morpholine, piperazine, piperidine, oxidation, lactam

Kinetics and Mechanism of Osmium(VIII)-Catalyzed Oxidation of Thiomorpholine by Alkaline Hexacyanoferrate(III)

Sun, 2014-01-05 14:59 — Mohammed Al-Subu'

Journal Title, Volume, Page:

Journal of Applied Sciences, 2002, Volume: 2, Issue: 7, Page No.: 742-746, DOI: 10.3923/jas.2002.742.746

Year of Publication:

2002

Link:

http://www.scialert.net/abstract/?doi=jas.2002.742.746

Authors:

Mohammed M. Al Subu

Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

[email protected]

Preferred Abstract (Original):

Thiomorpholine (tetrahydro-1,4-thiazine), in the presence of Os(VIII) as catalyst, is oxidized by alkaline hexacyanoferrate(III) to 2-hydroxythiomorpholine. There is a first-order dependence in [Fe(CN)₆^3-] and [Os(VIII)] and zero-order dependence in [thiomorpholine] and [OH^-]. The observed rate constant was dependent on [Fe(CN)₆^4-] the type of electrolyte and the permitivitty of the reaction medium (10-40% ethanol). The proposed mechanism includes the formation of a transient [OsO₄(OH)₂ ]^2--thiomorpholine complex prior to the rate-determining regeneration of Os^VIII by [Fe(CN)₆^3-]. The values of the enthalpy and entropy of activation are calculated from rate constant values measured at different temperatures (20-40 ° C).

Osmium(VIII)-Catalyzed Oxidation of Some Cyclic Amines by Potassium Hexacyanoferrate(III) in Alkaline Media: a Kinetics and Mechanistic Study

Sun, 2014-01-05 14:40 — Mohammed Al-Subu'

Journal Title, Volume, Page:

Chemistry of Heterocyclic Compounds April 2003, Volume 39, Issue 4, pp 478-484

Year of Publication:

2003

Link:

http://link.springer.com/article/10.1023/A%3A1024765330259

Authors:

M. M. Al-Subu

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

W. J. Jondi

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

A. A. Amer

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. Hannoun

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

M. J. Musmar

Department of Pharmacy, Faculty of Medicine and Health Sciences, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

Reactions of morpholine, piperidine, and piperazine with Os(VIII)-catalyzed hexacyanoferrate(III) in alkaline media to produce the corresponding lactam have been studied at constant temperature and ionic strength. The reactions followed first-order kinetics with respect to [amine] and [Os(VIII)] but were independent of [Fe(CN)₆ ^3-] and [OH^-]. The effects of introduced electrolytes, potassium hexacyanoferrate(II), relative permitivity, and temperature have also been studied. A mechanism accounting for these results has been proposed.

Kinetics And Mechanism of Oxidation of L-Cysteine By Ferrozineiron(Iii) Complex In Aqueous Acidic Medium

Mon, 2013-04-15 17:01 — Ismail Warad

Journal Title, Volume, Page:

Journal of Saudi Chemical Society

Year of Publication:

2006

Link:

http://blogs.najah.edu/staff/emp_2098/article/Kinetics-and-Mechanism-of-Oxidatio...

Authors:

Ismail Warad

Department of Chemistry, Girls College at Hawtat Sudayr, Saudi Arabia

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Maher AbuEid

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Bassem Sharydeh

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

Preferred Abstract (Original):

Kinetic oxidation of L-cysteine by [Fe(Fz)2]1- complex was carried out in acidic medium under pseudo rate conditions. The molar ratios between iron(III), iron(II) and Ferrozine (HFz) complexes in absence and presence of L-cysteine were individually determined using job's method. The formation of [Fe2+-Fz] at lmax = 562nm was spectrophotometrically followed during this kinetic study. The reaction is found to be first-order with respect to iron(III) and L-cysteine, second-order with respect to HFz-1 ligand and reversed second-order with respect to hydrogen ion concentrations. The salts effect was determined and no radical species have been detected. The kobs rose when the temperature was increased which empowered the activation parameters of the rate-determining step calculations. A reaction mechanism and rate law derivation are proposed with a pre-equilibrium of an adduct formation between L-cysteine and [Fe3+-Fz] complex.

One-Pot Combination of the Wittig Olefination with Bromination and Oxidation Reactions

Wed, 2013-03-13 16:18 — Ismail Warad

Journal Title, Volume, Page:

Synthetic Communications: An International Journal for Rapid Communication of Synthetic Organic Chemistry Volume 43, Issue 6, pages 893-898, 2013

Year of Publication:

2013

Link:

http://www.tandfonline.com/doi/full/10.1080/00397911.2011.614712

Authors:

Usama Karama

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

Refat Mahfouz

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

Zeid Al-Othman

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

Ismail Warad

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

Current Affiliation:

Department of Chemistry, Faculty of Science, An-Najah National University, Nablus, Palestine

[email protected]

Abdulrahman Almansour

Chemistry Department, College of Science, King Saud University, Riyadh, Kingdom of Saudi Arabia

Preferred Abstract (Original):

A simple one-pot process for in situ bromination of (ethoxycarbonylmethylene)-triphenylphosphorane 1 was carried out. This was followed by oxidation of alcohol using SO3. Pyridine complex as a mild oxidant and in situ trapping of the aldehyde. This process constitutes a stereoselective one-pot procedure for the preparation of Z-configured α-bromo-α, β-unsaturated esters in good yield.