Spectrophotometric Study of Catechol Oxidation by Aerial O2 in Alkaline Aqueous Solutions Containing Mg(II) Ions. |
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| Authors: | Goran M Nikolic Pavle I Premović Ružica S Nikolić |
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| Institution: | 1. Institute for Medical Chemistry Faculty of Medicine, University of Ni? Bra?e , Taskovi? 81, 18000, Ni?, Yugoslavia;2. Department of Chemistry Faculty of Science , University of Ni? ?irila i Metodija 2 , 18000, Ni?, Yugoslavia |
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| Abstract: | Electronic absorption spectroscopy was employed to study the aerial oxidation of catechol (1,2-benzenediol) in alkaline aqueous solution containing an excess of Mg(II) ions. Graphical analysis by the matrix method of UV spectra recorded at regular time intervals gave a good fit for two absorbing species in solution. Based on this result and our earlier ESR spectroscopic investigations we concluded that two main absorbing species in this system are Mg(II)-spin stabilized o-benzosemiquinone anion radical and C-C dimer formed by the nucleophilic attack of catecholate anion on o-benzoquinone. Although the formation of 1,2,4-benzenetriol during the catechol oxidation has been detected in some ESR studies its presence was not indicated by this analysis probably because of the low and/or stable steady state concentration throughout the experiment. |
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| Keywords: | catechol oxidation spectrophotometry |
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