Homogeneous oxidative coupling catalysts. Mechanism of conversion of 2,6-dimethylphenol [DMP] to 3,3′,5,5′-tetramethyl-4,4′-diphenoquinone [DPQ] by [(Pip)nCuX]4O2 (n=1 or 2, Pip=piperidine, X=Cl, Br or I) in aprotic media

El-Sayed, Mohamed A.; El-Wakil, Hoda A.; Kassem, Taher S.; Abo-El-Dahab, Hisham A.; Elkholy, A.

doi:10.1016/j.ica.2006.04.048

Cited by 6 publications

(1 citation statement)

References 11 publications

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“…This usually happens when Cl is changed to Br or I in similar core structures. [42][43][44] The cyclic voltammetry of 2 shows two anodic peaks potential at 0.716 and 0.898 V and two cathodic peaks at 0.731 and 0.530 V. We could not get any wave for the oxidation of copper(II) to copper(III) in the potential range up to 1.6 V.…”

Section: Supplementary Materialsmentioning

confidence: 88%

Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand

Vafazadeh

Willis²

2016

ACSi

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Two copper(II) clusters Cu 4 OCl 6 (pyrazole) 4 (1) and Cu 4 OBr 6 (Br-pyrazole) 4 (2) have been synthesized by reacting acetylacetone and benzohydrazide (1:1 ratio) with CuX 2 (X = Cl for 1 and X = Br for 2) in methanol solution. The structures of both clusters have been established by X-ray crystallography. The clusters contain four Cu, one O, six μ 2 -X atoms, and four pyrazole ligands. The pyrazole was prepared in situ by the reaction of acetylacetone with benzohydrazide in methanol under reflux. In 2, the methine hydrogen of the pyrazole ligand has been replaced by bromine atom. The four copper atoms encapsulate the central O atom in a tetrahedral arrangement. All copper atoms are five-coordinate and have similar coordination environments with slightly distorted trigonal bipyramidal geometry. The cyclic voltammogram of the clusters 1 and 2 show a one-electron quasi-reversible reduction wave in the region 0.485 to 0.731 V, and a one-electron quasi-reversible oxidation wave in the region 0.767 to 0.898 V. In 1, one irreversible oxidative response is observed on the positive of side of the voltammogram at 1.512 V and this can be assigned to Cu(II) to Cu(III) oxidation.

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Section: Supplementary Materialsmentioning

confidence: 88%

Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand

Vafazadeh

Willis²

2016

ACSi

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Oxidative polymerization of 2,6‐dimethylphenol to form poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water through one water‐soluble copper(II) complex of a zwitterionic calix[4]arene

Wan

Zhao

et al. 2012

J. Polym. Sci. A Polym. Chem.

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In the presence of excess NaOH, reaction of Cu(OAc) 2 ÁH 2 O with equimolar ammonium calix[4]arene [H 4 L]I 4 (1, H 4 L ¼ [5,11,17,23-tetrakis(trimethylammonium)-25,26,27,28tetrahydroxycalix[4]arene]) resulted in the formation of a mononuclear cationic Cu(II) complex [Cu(II)L(H 2 O)]I 2 (2) in 43% yield. Complex 2 was characterized by elemental analysis, infrared (IR), and single crystal X-ray diffraction. The Cu(II) atom in 2 is coordinated by four oxygen atoms of one L 4À ligand and one O atom from one water molecule, forming a square pyramidal geometry. Complex 2 exhibited high catalytic activity in the oxidative polymerization of 2,6-dimethylphenol using O 2 as oxidizing agent in water under mild conditions. The selective polymerization produced poly(2,6-dimethyl-1,4phenylene oxide) in high yields with almost no diphenoquinone. The influence of the polymerization temperature, the time interval, the molar ratio of 2,6-dimethylphenol/2, the concentrations of sodium hydroxide, and sodium n-dodecyl sulfate were examined. V C 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 50: [4864][4865][4866][4867][4868][4869][4870] 2012

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Manganese(III) porphyrin supported onto multi-walled carbon nanotubes for heterogeneous oxidation of synthetic textile dyes and 2,6-dimethylphenol by tert-butyl hydroperoxide

Rayati

Sheybanifard

2016

Comptes Rendus. Chimie

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Homogeneous oxidative coupling catalysts. Mechanism of conversion of 2,6-dimethylphenol [DMP] to 3,3′,5,5′-tetramethyl-4,4′-diphenoquinone [DPQ] by [(Pip)nCuX]4O2 (n=1 or 2, Pip=piperidine, X=Cl, Br or I) in aprotic media

Cited by 6 publications

References 11 publications

Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand

Synthesis, Structure and Electrochemistry of Tetranuclear Oxygen-Centered Copper(II) Clusters with Acetylacetone and Benz-pyrazole Hydrolyzed Derivatives as Ligand

Oxidative polymerization of 2,6‐dimethylphenol to form poly(2,6‐dimethyl‐1,4‐phenylene oxide) in water through one water‐soluble copper(II) complex of a zwitterionic calix[4]arene

Manganese(III) porphyrin supported onto multi-walled carbon nanotubes for heterogeneous oxidation of synthetic textile dyes and 2,6-dimethylphenol by tert-butyl hydroperoxide

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