Synthesis and catalytic activity of Cu (II) complex with 4-phenyl 2, 6-di (thiazol-2-yl) pyridine in the oxidation of para-aminophenol

Abstract

In the present work the synthesis of 4-phenyl-2, 6-di (thiazol-2-yl) pyridine copper chloride (abbreviated as Cu-DTPy) complex using copper (II) chloride and 2, 6-di (thiazol-2-yl) pyridine has been carried out. The complex has been specified by UV-Vis, FT-IR, CHNS and ESI-MS methods of analysis. The synthesized copper complex has been used as catalyst in the oxidation of p-aminophenol using hexacyanoferrate (III) ions as an oxidant in aqueous alkaline medium by kinetic-spectrophotometric method. This experimental work was carried out at optimum pH 11.0 and temperature 25ºC. The variation of effect of concentration of p-aminophenol (abbreviated as PAP), hexacyanoferrate (III) ions, and Cu-DTPy catalyst on reaction rate has been studied. Thermodynamic parameters such as free energy of activation, activation energy, enthalpy and frequency factor have been evaluated with the change in rate of the reaction at four disparate temperatures i.e. 25-40ᵒC. The oxidation products have been identified by FT-IR and ESI-MS spectroscopic analytical techniques. The major product of this reaction is NN’-bis-(p-hydroxyphenyl)-2-hydroxy-5-amino-1,4-benzoquinone di-imine. Thus, this method is highly efficient and environmentally safe to remove PAP from polluted water resources.