کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1229195 1495227 2015 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Copper(II) complexes as catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Copper(II) complexes as catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine
چکیده انگلیسی


• Copper(II) complexes of a bisbenzimidazolyl ligand are synthesised.
• Complexes catalyse the aerobic oxidation of o-phenylenediamine.
• Reaction follows first order kinetics with respect to substrate and catalyst.
• Rate of oxidation shows tenfold drop in absence of catalyst.
• Addition of acetate anion causes a mild inhibition of rate of reaction.

Two new mononuclear copper(II) complexes [Cu (L) (NO3)2] (1) and [Cu (L) Br2] (2) where (L = bis(1-(pyridin-2-ylmethyl)-benzimidazol-2-ylmethyl)ether) are synthesized and characterized by single-crystal X-ray diffraction analysis, elemental analysis, UV–Visible, IR spectroscopy, EPR and cyclic voltammetry. The complexes exhibit different coordination structures; the E1/2 value of the complex (1) is found to be relatively more cathodic than that of complex (2). X-band EPR spectra at low temperature in DMF supports a tetragonally distorted complex (1) while complex (2) shows three different g values suggesting a rhombic geometry. These complexes were utilized as a catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine assisted by molecular oxygen. The initial rate of reaction is dependent on the concentration of Cu(II) complex as well as substrate, and was found to be higher for the nitrate bound complex, while presence of acetate anion acts as a mild inhibitor of the reaction, as it is likely to pick up protons generated during the course of reaction. The inhibition suggests that the generated protons are further required in another important catalytic step.

Copper(II) complexes have been utilized as a catalyst for the aerobic oxidation of o-phenylenediamine to 2,3-diaminophenazine. Rate of oxidation in the absence of the catalyst shows a tenfold drop confirming the role of Cu(II) complex as a catalyst in this reaction.Figure optionsDownload as PowerPoint slide

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy - Volume 142, 5 May 2015, Pages 375–381
نویسندگان
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