2020-08-13Zeitschriftenartikel DOI: 10.18452/21717
New Insights into Catechol Oxidation – Application of Ammonium Peroxydisulfate in the Presence of Arylhydrazines
The oxidative polymerisation of catechols in the presence of amino groups is an important reaction leading to polymers or oligomers of great practical importance. We present here, the oxidative polymerisation in the presence of nitro‐substituted aryl hydrazines using ammonium peroxydisulfate (APS) as oxidizing reagent in the presence of Tris‐buffer. Mixtures of deeply coloured oligomers are formed and analysed by FTIR‐, NMR‐, ESR‐spectroscopy and, in particular, by HR‐ESI MS. The reaction occurred by C−C, C−O and C−N bond formation leading to aryl‐aryl, aryl‐O‐aryl, aryl‐N=N structural elements. In some cases, both N‐atoms of the starting aryl hydrazine have been lost during reaction. Remarkably, diaryl azo compounds as structurally similar with azo dyes were also formed. Their reaction with APS was investigated. These results provide new insight into the oxidative depletion of azo dyes with APS in industrial waste water treatment.