Fenoxilgyök es metil-fenoxilgyök kepzödese impulzusradiolizis sorän

Translated title of the contribution: Formation of henoxyl and methylphenoxyl radicals by pulse vadiolysis

Roder Magdolna, Wojnarovits Lâszlô

Research output: Contribution to journalArticle

Abstract

In acidic (pH ≈ 1,3-1,9) and alkaline (pH ≈ 11) aqueous solutions the reaction kinetics of the OH' radical induced o. Jalion of phenol, o-, m- and pcresol were studied by pulse radiolysis. The formation nineties of phenoxyl and melhylphenoxyl radicals, resp., are described by two, consecutive reaction steps: the first is addition of OH'radicals to llm aromatic ring, while the second H2O or OH elimination. The rate constants of the addition of OH'radicals are the same, (1,4) 1010 mol-1 dm3 s'1 for phenol and the three cresi isomers: this relates to diffusion controlled process. The rate constant of the adddition is nearly indej undent of the pH. The phenoxyl '.ad mcthylphenoxyl radicals are produced from the adducts in acidic solutions (pH = 1,3-1,9) by H2O elmination with a rate constant of (1,6±0,2) · 106s-1 but in alkaline systems (pH ≈ 11) by OH~ eliminnlioi with considerably faster reaction, (9-12) -10 s-1. The rate constants of production of methylphenoxyl radicals from cresol isomers are practically the same as that of phenoxyl from phenol: it means that the methyl substitution and the position of it influences neither the vulc of the OH-addition nor that of the H2O/OH- eliniation.

Original languageHungarian
Pages (from-to)354-358
Number of pages5
JournalMagyar Kemiai Folyoirat, Kemiai Kozlemenyek
Volume104
Issue number9
Publication statusPublished - Dec 1 1998

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ASJC Scopus subject areas

  • Chemistry(all)

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