# Radical Formation by Direct Single Electron Transfer between Nitrobenzene and Anionic Organo Bases

## TL;DR

This paper introduces a new method for creating stable radicals using nitrobenzene and anionic organic bases, enabling easier radical chemistry.

## Contribution

A novel single electron transfer mechanism for radical formation using common and inexpensive materials.

## Key findings

- Stable nitrobenzenide radical ion-pairs are formed from nitrobenzene and anionic bases.
- The method allows for radical transformations under mild conditions.
- Nitroarenes are identified as versatile precursors for heteroatom-centered radicals.

## Abstract

The presence of unpaired electrons, i.e., radicals, equips
organic
molecules with unique magnetic and reactivity properties. However,
due to the reactive nature of radicals and the nontrivial chemistry
required for their preparation, strict structural and electronic limitations
are imposed on the available systems, limiting their potential applications.
Thus, developing mechanisms that enable facile radical formation in
simple reaction conditions, employing available and inexpensive reactants
and applicable to general types of molecules, holds the key to capitalize
on the extraordinary properties that radicals have to offer. Here,
combining electron paramagnetic resonance spectroscopy and ab initio
calculations, we uncover an unprecedented single electron transfer
from multiple anionic organic bases (B–X+) to nitrobenzene [1], leading to the formation of stable
nitrobenzenide radical ion-pair [1

•–
]­[X

+
] (X = Li, Na, K)
and transient oxidized, radical bases B•. Our results
establish nitroarenes as versatile radical precursors, providing a
broadly applicable protocol for generating heteroatom-centered radicals
and enabling radical transformations under mild conditions from inexpensive
and readily available starting materials. Finally, we propose the
[1]–[B–X+] couple
as an unexplored platform with the potential to advance the field
of frustrated radical pairs.