First observation of tetranitro iron (II) phthalocyanine catalyzed oxidation of phenolic pollutant assisted with 4-aminoantipyrine using dioxygen as oxidant

A novel system for catalytic oxidation of phenol and chlorophenol pollutant in water by tetranitro iron (II) phthalocyanine (TNFe(II)Pc) is reported for the first time. In this system, several phenolic substrates (phenol, 2-chlorophenol, 4-chlorophenol and 2,4-dichlorophenol) could be easily oxidized by naturally dissolved oxygen in the presence of TNFe(II)Pc, and then rapidly combined with 4-aminoantipyrine to generate the pink dye. The catalytic oxidation process and resulting products were monitored by UV–Vis spectroscopy and high performance liquid chromatography–mass spectrometer (HPLC–MS) technique. Control experiments demonstrated that the generation of superoxide anion radical was crucial for the dye formation, and a possible mechanism involved a successive single electron transfer from phenolic substrates to O2 via the axis of TNFe(II)Pc was proposed. Potentially, this system is promising for application in chromogenic identification of phenolic pollutant.

Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (215 K)Download as PowerPoint slideHighlights► TNFe(II)PC could catalyze oxidation of phenol and chlorophenol pollutant. ► Dioxygen is oxidant and sufficient for the catalytic oxidation reaction. ► Superoxide anion radical is the active species generated in catalytic process. ► Successive single electron transfer is the key step of catalytic mechanism.