Related Experiment Video
Updated: Apr 13, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Crystalline Cyclic (Alkyl)(amino)carbene-tetrafluoropyridyl Radical
Steffen Styra1,2, Mohand Melaimi1, Curtis E Moore3
1UCSD-CNRS Joint Research Chemistry Laboratory (UMI 3555), Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093-0343 (USA) http://bertrandgroup.ucsd.edu.
Abstract:
A stable cyclic (alkyl)(amino)carbene (CAAC) 1 inserts into the para-CF bond of pentafluoropyridine, and after fluoride abstraction, the iminium-pyridyl adduct [3](+) was isolated. A cyclic voltammetry study shows a reversible three-state redox system involving [3](+) , [3](⋅) , and [3](-) . The CAAC-pyridyl radical [3](⋅) , obtained by reduction of [3](+) with magnesium, has been spectroscopically and crystallographically characterized. In contrast to the lack of π communication between the CAAC and the pyridine units in cation [3](+) , the unpaired electron of [3](⋅) is delocalized over an extended π system involving both heterocycles.
More Related Videos
Related Concept Videos
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Aromatic Hydrocarbon Cations: Structural Overview
Removing one hydrogen from the intervening CH2 group...
Aromatic Hydrocarbon Anions: Structural Overview
Due to the absence of continuous...
Radical Reactivity: Steric Effects
Along with electronic...
Radical Reactivity: Intramolecular vs Intermolecular
Radical Reactivity: Overview

