oxidation | An-Najah Staff

Investigation of the Catalytic Activity of Poly (Siloxane)-Supported Tetra (4-Pyridyl) Porphyrinatomanganese (III) in Olefin Oxidation Reactions

Wed, 2010-04-21 14:32 — Hikmat S. Hilal, D.Sc.

Journal Title, Volume, Page:

Journal of Molecular Catalysis Volume 81, Issue 2, 10 May 1993, Pages 157-165

Year of Publication:

1993

Link:

http://www.sciencedirect.com/science/article/pii/030451029380003D

Authors:

Hikmat S. Hilal

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

Current Affiliation:

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

[email protected]

C. Kim

Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204 USA

A. F. Schreiner

Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204 USA

Preferred Abstract (Original):

Supported tetra(4-pyridyl)porphyrinatomanganese(III), [Mn^III (TPyP)]⁺, has been used as a chemically regenerated catalyst for the oxidation of cyclohexene to cyclohex-2-en-1-one. NaBH₄ was used to reduce [Mn^III(TPyP)]⁺ back to its catalytically active Mn^III form. The reaction was selective to produce the cyclohexenone, and the catalyst showed high activity, with turnovers up to 14 × 10³. The effects of solvent, temperature, recovery, and reactant concentrations on the rate of the reaction have also been studied. The rate of the reaction was first order with respect to the catalyst. At higher olefin or oxygen concentrations the reaction was slower. A slower reaction was observed also in the absence of NaBH₄. The reaction was faster in nonpolar solvents than in polar ones. These results are also discussed.

The catalytic activity of poly(siloxane)-supported metalloporphyrins in olefin oxidation reactions: the effect of the support on the catalytic activity and selectivity

Wed, 2010-04-21 14:32 — Hikmat S. Hilal, D.Sc.

Journal Title, Volume, Page:

Journal of Molecular Catalysis A: Chemical Volume 113, Issues 1-2, 25 November 1996, Pages 35-44

Year of Publication:

1996

Link:

http://www.sciencedirect.com/science/article/pii/S1381116996000556

Authors:

Hikmat S. Hilal

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

Current Affiliation:

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

[email protected]

Waheed Jondi

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

Shukri Khalaf

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

Afaq Keilani

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

Mohammad Suleiman

Department of Chemistry, An-Najah N. University, Nablus, PO Box 7, West Bank, Palestine

A. F. Schreiner

Department of Chemistry, North Carolina State University, Raleigh, NC 27695-8204, USA

Preferred Abstract (Original):

Supported tetra(-4-pyridyl)porphyrinato-manganese(III) [MnIII(TPyP)]+ and -tin(IV) [SnIV(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 1-octene and of cyclohexene. NaBH4 was used to reduce [MnIII(TPyP)]+ and [SnIV(TPyP)]2+ back to their catalytically active MnII and SnII 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 [MnIII(TPyP)]+ catalysed 1-octene oxidation as well, whereas the supported [SnIV(TPyP)]2+ was inactive for the oxidation of 1-octene.

Kinetics and Mechanisms of Oxidation Of 1-Octene and Heptanal by Crown Ether-Solubilized Potassium Permanganate in Non-Aqueous Solvents

Wed, 2010-04-21 14:32 — Hikmat S. Hilal, D.Sc.

Journal Title, Volume, Page:

Transition Metal Chemistry, Volume 27, Number 2, March 2002 , pp. 223-227(5)

Year of Publication:

2002

Link:

http://www.ingentaconnect.com/content/klu/tmch/2002/00000027/00000002/00351576?c...

Authors:

Hilal H.S

Department of Chemistry, An-Najah N. University, PO Box 7, Nablus, West Bank, Palestine

Current Affiliation:

Department of Chemistry, An-Najah N. University, PO Box 7, Nablus, West Bank, Palestine

[email protected]

Al-Subu M.M

Jondi W.J

Dado S.A

Preferred Abstract (Original):

The kinetics of oxidation of 1-octene and heptanal by 18-crown-6-ether-solubilized KMnO_4 in benzene and CH_2Cl_2 have been investigated. In benzene, the oxidation of 1-octene is first order with respect to the oxidant and zero order with respect to the substrate, whereas in CH_2Cl_2 the reaction is first order with respect to both substrate and oxidant. The reaction of heptanal followed different kinetics being first order with respect to both substrate and oxidant, regardless of whether benzene or CH_2Cl_2 was employed as the solvent. The values of activation energy E_a, standard enthalpy Delta H^*, standard entropy change Delta S^*, and standard free energy Delta G^*, for the reaction, are reported. Mechanistic pathways for the studied reactions are also proposed.