Related Experiment Video
Updated: Mar 14, 2026
06:31
Preparation of SNS CobaltII Pincer Model Complexes of Liver Alcohol Dehydrogenase
Published on: March 19, 2020
7.7K
Redox Noninnocence in First-Row Transition Metal Complexes of a π-Extended β-Diketiminate
Lars Killian1, Bastiaan Bergwerff1, Björn Grabbet1
1Organic Chemistry and Catalysis, Institute for Sustainable and Circular Chemistry, Faculty of Science, Utrecht University, Universiteitsweg 99, 3584 CG Utrecht, The Netherlands.
Inorganic Chemistry
|March 12, 2026
Summary
New metal complexes with a π-extended benzo[f,g]tetracene β-diketiminate ligand were synthesized. These complexes exhibit unique redox properties, enabling the formation of stable radical species with delocalized electrons.
Area of Science:
- Coordination Chemistry
- Organometallic Chemistry
- Materials Science
Background:
- The development of novel ligands is crucial for designing metal complexes with tailored electronic and redox properties.
- π-extended ligands offer unique opportunities for charge delocalization and tuning electronic behavior in metal complexes.
Purpose of the Study:
- To synthesize and characterize novel homoleptic metal complexes using a π-extended benzo[f,g]tetracene β-diketiminate (BT-BDI) ligand.
- To investigate the structural, spectroscopic, and redox properties of these newly synthesized complexes.
- To explore the potential for radical formation and electron delocalization within the benzo[f,g]tetracene backbone.
Main Methods:
- Synthesis of homoleptic iron(II), cobalt(II), nickel(II), and zinc(II) complexes.
- Characterization using Nuclear Magnetic Resonance (NMR), Infrared (IR), and Ultraviolet-Visible (UV-Vis) spectroscopy.
- X-ray crystallography for structural determination of Ni(ClBT-BDI)2.
- Electrochemical studies (Cyclic Voltammetry, Differential Pulse Voltammetry) and Electron Paramagnetic Resonance (EPR) spectroscopy.
Main Results:
- Successful synthesis and characterization of homoleptic M(BT-BDI)2 complexes (M = Fe, Co, Ni, Zn).
- X-ray structure of Ni(ClBT-BDI)2 revealed a distorted tetrahedral geometry.
- Redox studies demonstrated the formation of monoradical [Zn(BT-BDI)2]·− and diradical [Zn(BT-BDI)2]2− species.
- Radicals were found to be delocalized across the benzo[f,g]tetracene ligand backbone.
- Nickel complex exhibited sequential reduction of metal and ligand upon electrochemical treatment.
Conclusions:
- The π-extended BT-BDI ligand is highly redox-active, facilitating the formation of stable radical anions.
- The benzo[f,g]tetracene core enables significant delocalization of radical character.
- These findings open avenues for designing new electroactive materials and catalysts based on extended π-systems.
More Related Videos
10:51The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
12.8K
06:53Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
2.8K
Related Concept Videos
03:02Colors and Magnetism
14.4K
Color in Coordination Complexes
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
14.4K
02:58Properties of Transition Metals
30.5K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
30.5K
02:51Metal-Ligand Bonds
25.3K
The hemoglobin in the blood, the chlorophyll in green plants, vitamin B-12, and the catalyst used in the manufacture of polyethylene all contain coordination compounds. Ions of the metals, especially the transition metals, are likely to form complexes.
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
In these complexes, transition metals form coordinate covalent bonds, a kind of Lewis acid-base interaction in which both of the electrons in the bond are contributed by a donor (Lewis base) to an electron acceptor (Lewis acid). The Lewis acid in...
25.3K
01:17Oxidation of Phenols to Quinones
5.1K
In the presence of oxidizing agents, phenols are oxidized to quinones. Quinones can be easily reduced back to phenols using mild reducing agents. The electron-donating hydroxyl group enhances the reactivity of the aromatic ring, enabling oxidation of the ring even in the absence of an α hydrogen.
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
o-hydroxy phenols are oxidized to o-quinones and p-hydroxy phenols to p-quinones. Such redox reactions involve the transfer of two electrons and two protons. The reversible redox...
5.1K
02:42Valence Bond Theory
11.5K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
11.5K
02:57Coordination Number and Geometry
19.4K
For transition metal complexes, the coordination number determines the geometry around the central metal ion. Table 1 compares coordination numbers to molecular geometry. The most common structures of the complexes in coordination compounds are octahedral, tetrahedral, and square planar.
19.4K