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Document Type |
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Article In Journal |
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Document Title |
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Homogeneous oxidative coupling catalysts: stoichiometry, characterization and kinetics of [(diamine)(μ-halo)copper(I)]2 oxidation by dioxygen in aprotic solvent Homogeneous oxidative coupling catalysts: stoichiometry, characterization and kinetics of [(diamine)(μ-halo)copper(I)]2 oxidation by dioxygen in aprotic solvent |
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Subject |
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Homogeneous oxidative coupling catalysts: stoichiometry, characterization and kinetics of [(diamine)(μ-halo)copper(I)]2 oxidation by dioxygen in aprotic solvent |
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Document Language |
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English |
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Abstract |
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Copper(I) halides dissolve in deoxygenated methylene chloride and nitrobenzene solutions of equimolar N,N,N'-triethylethylenediamine (TriEED) to give air-sensitive colorless or pale yellow copper(I) dimers [(TriEED)(μ-X)Cu]2, X = Cl, Br or I. Dioxygen uptake, analytical, cryoscopic and spectral data show that copper(I) dimers are oxidized to μ-oxo complexes, [(TriEED)2(μ-X)2(μ-O)Cu2], which react with carbon dioxide to form μ-carbonato analogues, [(TriEED)2X2(μ-CO3)Cu2]. Both oxo and carbonato complexes are homogeneous oxidative coupling catalysts for oxidation of 2,6-dimethylphenol to mixture of diphenoquinone (DPQ) and polyphenyleneoxide (PPO). Kinetic data for oxidation of [(TriEED)(μ-X)Cu]2 by dioxygen in nitrobenzene obey the third-order rate law d[[(TriEED)2(μ-X)2(μ-O)Cu2]]/dt = kD[[(TriEED)(μ-X)Cu]2]2[O2]. Comparison of the kinetic data with data for oxidation of [(TEED)(μ-Br)Cu]2, TEED = N,N,N',N'-tetraethylethylenediamine (the fully alkylated diamine), by dioxygen indicate that N-H in (TriEED) speeds the reaction by a factor of 220 due to an intermolecular attractive force between N-H of (TriEED) and the incoming dioxygen, helping to assemble the activated complex. |
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ISSN |
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1029-0389 |
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Journal Name |
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Journal of Coordination Chemistry |
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Volume |
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62 |
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Issue Number |
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4 |
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Publishing Year |
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2009 AH
2009 AD |
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Number Of Pages |
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13 |
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Article Type |
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Article |
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Added Date |
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Sunday, May 31, 2009 |
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Researchers
| Tahani A. | Tahani A. | Researcher | Doctorate | |
| Mohamed A. | Mohamed A. | Investigator | Doctorate | |
| Ibrahim A. | Ibrahim A. | Researcher | Doctorate | |
| Ahmed H. | Ahmed H. | Researcher | Doctorate | |
| Hisham A. | Hisham A. | Researcher | Doctorate | |
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