Evidence for a π Dimer in the Electrochemical Reduction of 1,3,5‐Trinitrobenzene: A Reversible N₂‐Fixation System

Abstract

Die elektrochemische Reduktion von 1,3,5‐Trinitrobenzol (1) führt zum π‐Dimer 2, das sich in einen stabileren σ‐Komplex umwandelt. Die Kristallstruktur des NEt4+‐Salzes von 2 zeigt Ketten aus Radikalanionen mit π‐Wechselwirkungen. Festes 2 oder dimeres 2 in Lösung bilden mit N2 ein Dianion, in dem eine Azogruppe zwei 1,3,5‐Trinitrobenzol‐Einheiten verbindet (siehe Bild). Das Azoderivat wird elektrochemisch reversibel zu 1 oxidiert.

Integrated Study of the Dinitrobenzene Electroreduction Mechanism by Electroanalytical and Computational Methods

“…However, the reaction of nitro group evaluation, as it was marked for RA both of aliphatic [48] and of aromatic nitro derivatives [49], cannot be yet considered typical for nitro compounds. Meanwhile, the reaction of the dimeric products generation was not once observed for RA of aromatic mono- [50,51] and polynitro compounds [38,52] and for DA [51].…”

Investigation on redox mechanism of 1,4-naphthoquinone by in situ FT-IR spectroelectrochemistry

“…It has been demonstrated that the formation of π-dimer occurs prior to formation of σ-dimer , in addition, a π-dimer forming reaction is very rapid with relatively small equilibrium constant and a σ-dimer forming reaction has a slow rate with large equilibrium constant [18,27,32]. There are still three couples of anodic and cathodic peaks for Q in the thin-layer cell under a A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 10 high potential scan rate (v= 50 mV/s, not shown).…”

“…The electrochemical redox process, including the possible electrode reactions and proton-transfer reactions, can be depicted by the well-known nine-membered square scheme [6,16,17]. Dimerization is one of the significant organic radical reactions [18][19][20][21][22][23].…”

Bidimensional Spectroelectrochemistry: application of a new device in the study of a o-vanillin-copper(II) complex

“…Spectroelectrochemistry (SEC) is a powerful instrumental technique that combines two classical analytical techniques, such as electrochemistry and spectroscopy, to obtain in situ chemical information [1][2][3][4][5][6] about the reactions taking place during an electrochemical experiment. Usually, the electrochemical technique controls the chemical process, while spectroscopy provides molecular information about chemical compounds involved in the process, being complementary to the electrochemical information.…”