Related Experiment Video
Updated: May 20, 2026
06:53
Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks
Published on: June 9, 2023
Decomposition of Magnetic Coupling in μ-Oxo-Bridged Metal Complexes
1Department of Chemistry, Quantum Chemistry, TU Darmstadt, Peter-Grünberg-Str. 4, 64287 Darmstadt, Germany.
Journal of Chemical Theory and Computation
|May 19, 2026
Summary
The valence intermediate effective Hamiltonian (VIEH) approach was adapted for multiple magnetic pathways. This method reveals that weakening antiferromagnetic coupling in metal complexes is due to increased ferromagnetic contributions.
Area of Science:
- Inorganic Chemistry
- Computational Chemistry
- Quantum Chemistry
Background:
- Magnetic coupling strength in metal complexes is crucial for understanding their properties.
- The valence intermediate effective Hamiltonian (VIEH) approach is a standard method for analyzing magnetic coupling.
- Existing methods may not fully capture complex magnetic interactions in systems with multiple pathways.
Purpose of the Study:
- To adapt the VIEH framework for analyzing magnetic coupling in complexes with multiple interaction pathways.
- To investigate the contributions of ferromagnetic and antiferromagnetic interactions in a series of metal complexes.
- To explain the trend in magnetic coupling strength across different metal ions.
Main Methods:
- Adaptation of the valence intermediate effective Hamiltonian (VIEH) framework.
- Application to a homologous series of [M2(μ-O)(NH3)n]2+ complexes (M = Cu, Ni, Fe).
- Decomposition of magnetic coupling into ferromagnetic and antiferromagnetic components.
Main Results:
- The adapted VIEH approach successfully handles multiple magnetic coupling pathways.
- Antiferromagnetic coupling strength decreases progressively from Cu(II) to Ni(II) and Fe(II) complexes.
- The observed decrease in antiferromagnetic coupling is attributed to a concurrent increase in ferromagnetic coupling contribution.
Conclusions:
- The modified VIEH approach provides a robust method for dissecting complex magnetic interactions.
- The balance between ferromagnetic and antiferromagnetic contributions dictates the overall magnetic behavior.
- Understanding these contributions is key to designing materials with specific magnetic properties.
Related Concept Videos
03:02Colors and Magnetism
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 eye.
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 eye.
02:42Valence Bond Theory
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...
02:58Crystal Field Theory - Octahedral Complexes
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
01:09Complexation Equilibria: Factors Influencing Stability of Complexes
In complexation reactions, metal cations are the electron pair acceptors, and the ligands are the electron pair donors. The stability of the metal complexes depends primarily on the complexing ability of the central metal ion and the nature of the ligands. Generally, the complexing ability of the metal ion depends on the size and charge of the ion. As the metal ion size increases, the stability of the metal complexes decreases, provided that the valency of the metal ion and the ligands remain...
02:51Metal-Ligand Bonds
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...
02:32Bonding in Metals
Metallic bonds are formed between two metal atoms. A simplified model to describe metallic bonding has been developed by Paul Drüde called the “Electron Sea Model”.