Unusual reactivity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with Fe controlled by competing reactions.

2,2-Diphenyl-1-picrylhydrazyl (DPPH) is a stable organic free radical widely used in various fields as a model free radical. There is scarce information about the stability of this compound in the chemical environments in which it is used. Side reactions between DPPH and other species can alter the precision of experiments that use DPPH, such as the evaluation of antioxidant properties amongst others.

Probing the reactivity of 2,2-diphenyl-1-picrylhydrazyl (DPPH) with metal cations and acids in acetonitrile by electrochemistry and UV-Vis spectroscopy.

2,2-Diphenyl-1-picrylhydrazyl (DPPH) is certainly one of the most widely used free radicals in several applications, because of its high stability. Unfortunately, there are few works dealing with its stability in the presence of many chemical species that coexist during chemical processes. In this work, the stability of DPPH was investigated by electrochemistry and UV-Vis spectroscopy in the presence of some metal cations (Cu and Zn) and acids (HClO and HNO) in acetonitrile.