Influence of Methyl Substituent Position on Redox Properties of Nitroaromatics Related to 2,4,6‐Trinitrotoluene

Abstract

The environmental remediation of military installation sites is very important due to frequently large presence of carcinogenic derivatives of explosives in the ground and in ground waters. These nitroaromatic explosives and their derivatives are assessed by sensing devices. It is highly important to have insight on the reasons affecting the reduction potentials of these compounds. The redox properties of mono-, di-and tri-nitroaromatic compounds are studied with cyclic voltammetry at a glassy carbon electrode for comparison. We show that the presence of a methyl group in the aromatic system leads into more negative reduction potentials. The ease of nitro group reduction vary from meta > para > ortho positions relative to a methyl group. The redox properties were also studied at various pH ranging from 2 to 10. Acidic environments facilitated the reduction processes at lower potentials. These findings will have a profound influence upon understanding the processes during reductive decontaminations of the polluted sites as well as for construction of highly sensitive sensors for their determination.

Spectroscopic and Electrochemical Characterization of Iron(II) and 2,4-Dinitrotoluene

“…The peak at −0.9 volt may be attributed to the electrochemical reduction of 2,4-dinitrotoluene and has been described previously (Chua and Pumera 2011; Zhang et al 2011; Fierke et al 2012; Caygill et al 2013; Wang et al 2014). The reduction occurs via two reaction steps: a four-electron reduction of the nitro group produces a hydroxylamine group, followed by conversion to an amine group.…”

Mesomeric Effects of Graphene Modified with Diazonium Salts: Substituent Type and Position Influence its Properties

“…The cyclic voltammetry of the substituted benzene modified samples in PBS are shown in Figure 9. The strong reduction peak starting at about −0.3 V originates from nitro group reduction 35. The nitro group is reduced to a nitroso group in a 2 e − step and immediately to hydroxylamine in the following 2 e − step.…”

“…The strong reduction peak startinga ta bout À0.3 Vo riginates from nitro group reduction. [35] The nitro group is reduced to an itroso group in a2 e À step and immediately to hydroxylamine in the following 2e À step. As the reduction potentialo f -NO 2 to nitroso is larger than that of the nitroso group to hydroxylamine, one observes a4e À reduction step.…”

Nitroaromatic explosives detection using electrochemically exfoliated graphene

“…comparing the electrochemical and fluorescent detection methods for TNT analysis based on carbon quantum dots, a broader linear detection range was possible for the electrochemical sensor 25 . Electrochemical detection of DNT and TNT are made possible by the 4-electron stepwise reduction of each –NO 2 group to an –NHOH group 6 followed by the 2-electron reduction of –NHOH group to an –NH 2 group 26 27 .…”