Related Experiment Video
Updated: Jul 19, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
[CpNi(dithiolene)] (and diselenolene) neutral radical complexes
Mitsushiro Nomura1, Thomas Cauchy, Michel Geoffroy
1Laboratoire Chimie, Ingénierie Moléculaire et Matériaux d'Angers (CIMMA), UMR 6200 CNRS, Université d'Angers, UFR Sciences, Bât. K, 2 Bd. Lavoisier, 49045 Angers, France.
This study synthesized five neutral radical organometallic complexes, including [CpNi(dddt)], achieving an 86% yield. These complexes exhibit reversible redox behavior and strong near-infrared absorption, with structural analysis revealing unique magnetic interactions.
Area of Science:
- Organometallic Chemistry
- Materials Science
- Spectroscopy
Background:
- Neutral radical complexes are of interest for their unique electronic and magnetic properties.
- Nickel-dithiolene complexes have shown diverse applications in materials science.
- Understanding structure-property relationships is crucial for designing novel functional materials.
Purpose of the Study:
- To synthesize and characterize a series of neutral radical organometallic nickel complexes.
- To investigate the electrochemical, spectroscopic, and magnetic properties of these complexes.
- To correlate structural features with observed magnetic behaviors.
Main Methods:
- Synthesis of [CpNi(dddt)] and related complexes using various nickel precursors and dithiolene transfer agents.
- Electrochemical studies to determine redox potentials.
- UV-Vis-NIR spectroscopy to analyze electronic transitions.
- X-ray crystallography for molecular and solid-state structure determination.
- Magnetic susceptibility measurements.
Main Results:
- Successful synthesis of five neutral radical complexes: [CpNi(dddt)], [CpNi(ddds)], [CpNi(dsdt)], [CpNi(bdt)], and [CpNi(bds)].
- Optimal yield of 86% for [CpNi(dddt)] achieved via reaction of [CpNi(cod)](BF4) with (NBu4)[Ni(dddt)2].
- All complexes exhibit reversible oxidation and reduction.
- Strong NIR absorption observed, with band positions dependent on the dithiolene ligand.
- X-ray structures reveal isostructural relationships within ligand series and unique Cp...Cp sigma overlap in [CpNi(bdt)] and [CpNi(bds)].
- Magnetic measurements indicate alternated spin chains in dddt/ddds/dsdt complexes and strong antiferromagnetism in bdt/bds complexes.
Conclusions:
- The study successfully prepared and characterized a new series of Ni(III) radical complexes.
- The complexes display tunable NIR absorption and reversible redox activity.
- Distinct magnetic behaviors, including spin chains and strong antiferromagnetism, are linked to specific ligand structures and intermolecular interactions.
Related Concept Videos
Diels–Alder Reaction: Characteristics of Dienes
Characteristics of the diene
Conformation
The simplest example of a diene is 1,3-butadiene, an acyclic conjugated π system. At room temperature, the molecule exists as a mixture of s-cis and s-trans conformers by virtue of rotation around the carbon–carbon single bond. Although the s-trans isomer is more stable, the...
[4+2] Cycloaddition of Conjugated Dienes: Diels–Alder Reaction
Radical Reactivity: Nucleophilic Radicals
Radical Reactivity: Electrophilic Radicals
Radical Reactivity: Overview
Electrophilic 1,2- and 1,4-Addition of X2 to 1,3-Butadiene

![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)