Studying the effect of substituent on the electrochemical reduction of nitrobenzene and its Derivatives

Abstract

This paper reports a comprehensive study about electrochemical reduction of nitrobenzene and its derivatives ortho- meta- para-nitroaniline and para-nitrobenzaldehyde in mixed aqueous organic media (5% methanol,KCl 0.5 M) by polarographic cyclic voltammetry on Dropping Mercury Electrode(HDME). The results showed that all  derivatives  gave a sharp irreversible well-defined peak on (Hg) Hanging Dropping Mercury Electrode(HDME) in a reaction involving four electrons  to give the hydroxylamine  derivative. In this medium meta-nitroaniline is easier reduced in approximately 80 mV than that of the ortho-nitroaniline. It was observed that para- nitrobenzaldehyde is easier reduced than para-nitroaniline because it has electron-  withdrawing substituent.

Key words: polarography, cyclic voltammetry, nitrobenzene, Hanging Dropping Mercury Electrode (HDME).